Sorry if this is in the wrong forum i have no idea where to post these anymore :S.

Anyway, I'm changing from the pill Dianette to Loestrin because my skin cleared up and I prefer Loestrin as my regular pill.
To change you need to take the first pill of Loestrin straight after the last Dianette pill, which means I won't have my period.
However, I really need my period this month, so I was thinking of taking the new pill on the first day of bleeding like you would if you hadn't been on the pill at all before. Is this a bad idea? I'm just guessing I won't be fully protected, contraception wise, for a week but that doesn't bother me. So should I, or should I not?

There are two ways of switching pill. If you don't want to lose contraceptive protection, you should take the new pill the day after you finish your old pill packet.

HOWEVER if you don't mind losing contraceptive efficacy for the first week, then take a pill break as normal, and seven days later, when you normally start taking the pill again, start taking your new pill. You won't be protected for the first week, and if you want to be super cautious you should consider protection for the whole cycle, however its a pretty well established way to change pills. Thats what I did when I swapped from Marvelon to Microgynon. Waiting til you start bleeding is the worst plan, because that will make you spot all the way through your next packet.

Here is what the British National Formulary (what the doctors use) says:

Changing to combined preparation containing different progesterone


21-day combined preparations: continue current pack until last tablet and start first tablet of new brand the next day. If a 7-day break is taken before starting new brand, additional precautions (barrier methods) should be used during first 7 days of taking the new brand.

Thankyou! I'll do the normal seven day break then.

Yeah, I would. Its a better way to change pills- you get less breakthrough bleeding (even if you do lose 7 days of contraceptive efficacy).