My period is usually regular. lasts 5-7 days every month. this month it only lasted 1 day. now i have a horrible headache. pregnant maybe?

Do a quick HPT: Home pregnancy tests are easy to do, fast, and highly accurate. So, u can get this answer in just a few minutes. Every normal menstruating female experiences some symptoms/changes of her cycles during the reproductive years, so it is hard to tell from what you experience; even being on the pill you can still get pregnant--chance is low. If you have additional concern, consult doc. Good luck.