Pregnant or not Pregnant, that is the question.

Well this is my third post regarding if I may be pregnant or not... And I'm super nervous and need some advice. I posted last week that I took a test on 9/20 and 9/21 and they both resulted in positive, and then I took one on 9/23 and it was negative (which in a few hours resulted in a really faint line) . A couple people answered before the faint line appeared saying it may be a chemical pregnancy which I was so sad about. Then on Sunday, I woke up around 6AM with morning sickness. I was trying so hard to keep the vomit down, and even woke up my SO and he was trying to calm me down and help me any way he could.  It lasted about 30 min or so and felt a bit nauseous here and there throughout the day and today as well but still not vomit thank goodness! Anyway, I took another pregnancy test and it seems negative. There might have been something there but it might have been playing tricks on me. I'll also add I'm 3 days late and emotional. I've been crying like a baby.  I was supposed to start my period on Saturday but nothing. I'll definitely wait to retest tomorrow morning, but does this mean I'm not pregnant? Still a chemical pregnancy? Has anyone experienced this?