Can I be pregnant?

Me and my fiancé had unprotected sex on the 29th of August and I got my period 2 days later but it came light for 2 days then stopped then it got heavy all of a sudden and my period just stopped last week and it started a couple days ago where my boobs are sore, tender and they hurt really bad. I'm having some cramps mostly on my left side but die down during he say then come back a little while after and I had back pain but it's gone away a bit. Is it too soon to be having symptoms? I feel exactly as if I would be getting my period tomorrow but I just finished my cycle could this mean I'm pregnant?