Could it be endo?

First I have regular periods. They last 3-4 days and I have a 29 day cycle. I don't have cramps that often or that painful. However I do have stabbing/ripping pain on my period. It's really bad when I have a BM. It's been going on about a year and sort of getting worse. I only have pain when I'm on my period. Could it be endo? Or something else? I'm a pretty healthy 21 year old.

I'm going to my primary next week for my pap so I'll talk to her about it then. Just wanting to get some opinions. I'm terrified about my fertility since we're going to ttc next year some time.