bc causing pregnancy symptoms?

Can birth control cause pregnancy symptoms like nausea in the mornings or headaches ect. Ive been on it for 7 and a half weeks now and im so scared im pregnant. I had sex 4 times, 13 days after starting it because it says to take for 7 days before unprotected sex, i hadnt missed any. I took a test last week and got a bfn but maybe i was testing to early? it was about 3 and a half weeks after having sex and i didnt use first morning urine. I havent had a period since starting the pill but i never did on the same pill before either, its more the nausea and things im worried about, i do have anxiety. I plan on testing again, when would be best? Its been 5 weeks today since unprotected sex. I didnt test until 9 weeks with a digital with my daughter because i was 18 and too scared to test so im unsure if im maybe too early for a positive on a dye test? Help!