Hey there's a lot of info for this
I'm 21yrs old, my period is 20 days late today, I have a ovarian cyst on my right Overy, I had unprotected sex on the 7th sept but my boyfriend withdrew, I have seen my gyn and am having a hysteroscopy next month. I have taken 4 pregnancy tests in the last 2 weeks and all have come out negative... I did have a problem with bleeding for 5 months which stopped in August... last period finished on the 6th sept. I don't know what's going on my gyn won't explain anything to me... am I not pregnant?

It could be too early to test. Wait until your next period is due. If you miss it than test again, make sure to use first morning urine when you test.