scared😭

the past two weeks ive been nauseated and feeling like im going to throw up my tummy hurts and so dose my head. im on the shot but ne and my bf have sex almost every week. he hasnt ever cumed in me but i dont know whats wrong im scared i could be pregnant will someone help me? i dont know how i could be pregnant if he didnt cum in me and im on the shot. im really worried.