I don't know what's going on

From the last period I suffered from really bad cramps (like at first I'm ok and then I have a cramp that makes me cry).

Then 8 days before my supposed period I felt some PMS like tender breast, acne and the cramps where not as bad as before.

Now my period is 3 days late, I have diarrohea, another time really sever cramps (and my right nipple is always itchy but I don't think it matters)

From the last 2 period i notice it is always late (before was 28 days and now i think it changes in 32/34)

I'm scared I have polycistic ovaries sindrom like my mom....

Please help me!!