Cramps?

5 DPO had sex on day 5 of ovulation & again 2 days ago my period isn't scheduled to start for another 8 days but I'm having some cramps.. Does this sound familiar to anyone? I don't ever get pms symptoms i typically only get cramps during my actual period on heavy days.. We're TTC this month, I am hopeful but these cramps are making me a little concerned.. Could I be starting my period early?