On and off vaginal bleeding- I’m scared

My period has been regular my whole life… I’m scared because I started bleeding 2 weeks ago and it was a week after my period. We had intercourse a couple days before I started bleeding… I thought maybe it was from that or ovulation. It was enough to fill up a regular tampon in 3-4 hrs for almost a week… then it stopped for a week. Now, the bleeding is back and this discomfort that’s almost like a period discomfort but not the same

I’ve been researching and thinking the worst now- cervical or uterine cancer.

It could be fibroids or polyps too?

I don’t know- I’m scared and of course will make an appointment now immediately tomorrow