Birth control

Can birth control make you nauseous hours after you take it? I take mine right before I go to bed (12am) and lately every afternoon (1-6) I get nausious. I am just curious. I don't think I'm pregnant. In fact I'd be extremely surprised because I'd be pretty far along then. So I highly doubt that. But I've been consistently nauseous in the afternoon for like a week now. I just switched to a new birth control pills and I'm thinking that's it. I'd appreciate any comments that will give a clearer answer. Thanks !