What’s going on??

Hello , I am Lala. I have been trying to get pregnant for about 6 years now. I am 25 years old . A little on what has been going on lately. So I had a period feb. 26 I am a 7 day girl so it ended on the 4th of March. In March I got another period a week apart from the other one which started in February and ended in March. So March 17th it started again ended on the 23rd. I was supposed to get my period on the 14th of April so my period tracker says. But I didn’t get it. Still haven’t , on the 18th I went to the bathroom and there was a little bit of spotting not a lot just a little . I assumed it was my period and put on a pad . As the day go by the bleeding did not continue I bleed just that one time I went to the restroom and seen the blood. Now here is where it get kinda crazy Friday the 13th of April I had a appointment with my obgyn and she put in and order for a ultrasound to check my uterus and fallopian tube‘s and etc. so I went to that appointment on the 20th of April. At this point I’m thinking i could be pregnant because at the point I am 16 days late so I take a test on the 20th of April it was negative. I was cramping 2 weeks straight but no period no nothing . So on Thursday I got a call about the results of my ultrasound everything is normal there is nothing wrong she also told me I was not pregnant.. which brought me to tears cause I don’t know what’s wrong with me. It’s April 28th and I still don’t have my period. What’s going on ??