I just switched birth control pills a week from today. i feel nauseous, acid reflux,stomach aches. i had sex 3 days after switching. am i pregnant?

Maybe: Its more likely that you aren't tolerating the current pill, so if it occurs with the next pack that's the issue. I tell all of my patients to use a condom back up when they switch pills (dose or brand name) as the pregnancy rate is slightly higher when you switch, so yes please check a pregnancy test.

Probably not: If you did not miss any pills and switched straight to the new pill, pregnancy is not likely (although there is a SLIGHT cause of pregnancy with the pill). The timing is too soon. Certain medications(antibiotics, topamax) can make the pill less effective. It is more likely that the new pill is giving side effects. And don't forget the pill does not prevent sexually transmitted infections. Condoms!