I have been off my period for 3 days. but i feel like im going to start again, why do i still got pms symptoms, bloating and cramps/sharp pains?

Please see your Gyn: This doc is concerned. Many possibilities at this age. Let's agree you will call tomorrow. If you use a clinic rather than a gynecologist, fine. Call your usual place. And time needs to be on your side. Really. Best wishes because you will call tomorrow. I will not scare you into getting care, but this is serious until proven otherwise. I want this to be as easy as can be, dr. Hoffman.