BFN and sickness!?

I’m not due to start my period until the 23rd or 24th, I’ve taken a few pregnancy tests and they were all BFN. I’ve been getting sick to my stomach the past few days. You know that feeling you get when your about to throw up. Some people call it sweaty mouth or hot mouth. Plus normally i cramp 2 weeks up until i start my period. I’ve had zero cramps. Can you have morning sickness before you get a positive?? Or has anyone gotten BFN with sickness and you were in fact pregnant just to early to detect by a pregnancy test?!