Pls help!

So I was supposed to start my period on the 22nd and haven't started yet (yes I've had sex recently) I woke up today throwing up but as for the other symptoms of pregnancy I'm not having those. I don't have swollen breasts, or cravings, but I do have diarrhea. (Sorry for the TMI) I tried taking an early clear blue pregnancy test and it came out negative, but could I be pregnant??