It is a concern. Being on bc pills can make you irregular period wise simply because of the wrong mix of hormones. Hopefully, with some trial and error, though, you'll get extremely regular on them. However, yeah, when you get off them you could be irregular. It usually only lasts a few months till your body balances out again but there are a few people who just never seem to get back on track. Though i'm sure that's not to common. Normally, a doctor says you'll go back to whatever you were like before the pills. But there's always a chance you may not. That's actually why i'm terrifed of giving up on the pill.

As long as you get on a pill that reacts well with your body then you shouldn't get irregular.
And yes, when you go off of the pill you will most likely be irregular for a couple of months. I never had regular period anyway, but when I went off of the pill it was really messed up. After a year of that I went back on the pill. I don't know what I am going to do when I hit my thirties and my doc tries to take me off of the pill!

I was on the pill for many years.After I turned forty,the docs became worried because I developed severe mensrual migraines and worried I would have a stroke.I was taken off the pill in late april and my body is still trying to work things out.I get my period every 2-3 weeks and it is worse that I remember.I know I need to be pateint,but I can't wait for menopause!I miss my pills!!!!I don't have any advice,just wanted to vent!Patty

Yeah, I am not looking forward to that at all. I have been on the pill for about nine years maybe ten and I don't want to go off of it. But when I hit late 30's or early/late 40's, I know that docs try to get their patients off of the pill. Blah!

Is it guaranteed to give you irregular periods after you get off bc? I know that if you don't finish a cycle and just quit, you can be irregular, but what if you take them to the end of each pack, would that help? I dont want to have irregular periods from now on!! What the hell?? I had no clue about this when I was researching...

It isn't a guarantee, no. Nothing is. But, when your body gets used to something (anything, not just meds or b/c pills) and that something is taken away there are most likely going to be side effects. Some people are fine after about a month of being off of it, some take a year or more and some just never have a regular period. It just depends on your body, age, health and if you had regular periods to being with or not.