I got my period a little over a week ago and I am on birth control. I switched up 2 of my pills from my last pack, but I haven't messed up before or after that one time. I've been on tri-sprintec for about 9 months now. I'm just concerned I might possibly be pregnant? I've been experiencing some symptoms similar to pregnancy like not having much of an appetite and acid reflux. Is it possible for me to be pregnant?