Really long, but please read, I need some advice
Ok so basically, I'll start off by saying I'm 30 weeks pregnant and that I've been with my man for about 2 years. I've always thought we had a great relationship but he's been up to things recently that don't add up and I'm not sure what to do.
About 3/4 years ago he had a one night stand with a girl he went to school with, he told me when we were talking about our ex's and he proclaimed that the sex was amazing and she was so fit and that they were at it all night etc etc (which instantly made me jelous and insecure) Last year he started talking to her on msn which I didn't mind at all and she added me to her friends list and we even had a few nice convos. A couple of months after they started talking, she started sending my boyfriends pictures of herself through msn, and his mobile. This made me feel uneasy because she is certainly pretty and slim (I must add I'm really insecure, maybe it wouldn't have bothered other people so much) The pictures started getting raunchier and raunchier until it was pictures of her bent over with only panties on. As you can imagine I went crazy. I had a right go at her and her reply was something along the lines of 'Im sorry, the attention makes me feel good' or some shite like that. My boyfriend didn't seem to understand that she shouldn't be doing shit like that and said they were innocent and how could he not accept them? from then on I got upset when he spoke to her online or text her and I started checking his phone alot.
A few months aftet that I was out drinking with my sister and I came home and passed out on our bed, my boyfriend was sitting next to me on his laptop on msn. The next morning I was on the laptop and just thought I'd check to see if firecrotch had been up to her usual tricks, I found 3 pics of her in the nude, a map of where she lived and an msn conversation with my boyfriend calling her a "hottie" and how they had to meet up to catch up. I was really upset and begged him not to meet up with her, he told me he wouldnt and that I shouldnt get so upset cause its just a bit of fun. About a week after that, my boyfriend put a screen pin lock on his phone so I couldnt access any folders or anything and one night when he was at my parents house with me, he announced he was going to his brothers house and that they were going to be drinking so he was just going to stay over. I didn't think anything of it until I was sitting next to him on the couch and a text message came through on his phone, from her, saying "where are you picking me up? cant wait to see you" he told me he lied to me because otherwise he wouldnt be able to meet her without me giving him grief. damn right! i was soo pissed off and he went out but came back about midnight saying that they went for a drive and had fun and that nothing happened (next day when i got in the car the heater setting for desteaming the windows was on..prob a coincidence but still) after that the msn conversations and texts dried up and everything was hunky dory for a bit. oh I forgot to add, he went to see her on xmas eve last year as well but only found out a couple of months ago. well, i thought it was over and done with and that she was out of our lives forever (wishful thinking) last week my boyfriend started talking to her again on msn and they arranged to meet up, he asked me first and i was like yup ok thats fine as long as you let me know and dont lie to me about it. on monday he finished work at 6pm and i got a phonecall at 8pm (after making his dinner and then having to chuck it out cause it was cold and ruined) from him saying "is it ok if i go meet up with *her* for a minute" and i thought he'd just be going to see her on her break from work or something cause I know she works till 10pm i assumed he'd be home about 9ish or something but he didnt get back till like midnight and it turned out he went to her flat (where she lives alone, his new job is just round the corner from her flat) and then they went out for a drive. although i had to prize the story out of him, he told me first of all, he went to his parents house first when he finished work (they live in the other side of town) then went to meet her, then went back to his parents house, then drove half way home, turned back and went back to his parents house (confusing i know, his stories dont add up) i was really upset at this point because god knows what he was doing all night, my mind likes to paint me pretty pictures. anyway, when he got home he was acting really nice to me, brought the washing in without being asked to and kept telling me how i was his beautiful baby girl and shit like that, which made me instantly think, ok, whats he been up to. i asked him if he planned to meet up with her again and he told me that they had arranged to go to the pub on sunday night and that her friends were going as well (although i now think this may be a lie to make me less paranoid about them being alone and drunk) and i said oh great, will be good to finally meet her (i was trying to be optimistic and give him the benefit of the doubt) he then told me "oh, you're not invited, its friends only"

WTF?? i then said, what, am i not your friend now? and he said "well its just friends that we both know..and you're pregnant anyway, you cant drink" so fucking what. god im so hurt, i feel like he's either embarassed of me, or its a cosy wee drink between her and him and thats the real reason im not invited. i told him he wasnt going without me and then he said, "oh i wont go then" and he told me this morning he cancelled. he keeps deleting the txts out of his phone as well. i was playing with his phone last night and he took it off me, deleted his calls logs, sent messages and inbox messages. He also was searching for pictures of her on photobucket and google (pathetic eh?) anyway. I dont know what to think. her hairbobble was on the floor of the car yesterday and it made me feel so uneasy knowing she'd been in our car and god knows what could of happened. when i asked him whos bobble is was he had a big smirk on his face and went "ehhh". am I off my head? is this normal behaviour? I don't know if I should be paranoid or if its these crazy pregnancy hormones. I'm sorry if this story is a lil confusing, I'm so confused myself.