My boyfriend and I had unprotected sex about a month ago. I am taking birth control, but the way my prescription is set up I only have my period every 4 months, so my cycle has never really been consistent... it normally comes one week late, after I start taking my birth control again. I was expecting it sometime this week, but has not happened yet...

What are a few very early signs I can look for?
It it normal that my period always comes somewhat late?
How accurate is birth control?
It it possible my body just isn't ready for my period?
Is it possible I'm a month pregnant?

If you had unprotected sex a month ago and you're worried, take a pregnancy test. It's been long enough that you should get a result one way or the other. You should also call your doctor about the missed period and possibly arrange for an STD test since you were having unprotected sex, if you and your partner weren't tested previously.

When you take it perfectly, birth control is over 99% effective in preventing pregnancy. Keep in mind that most people don't take it perfectly, making it closer to 94%, which is still way better than nothing.

There's a list at the top of the "Women's Health" section of this forum that goes through the usual pregnancy symptoms.