Could I be pregnant?

[keeppositive]

Hi guys im new here so bare with me trying to use it
Could someone please give me there opinion and advice on my situation.
Me and my partner have unprotected sex quite regulary. We had it while I was fertile but not on the day I ovulated,the day before we did. A week after I ovulated my stomach start feeling really weird and I was getting uncomfortable twinges and cramps, mailnly in my left side,the cramps were pretty bad. I usually get cramps 1/2 days before my period but this was a week before. Done a test and it came back negative. So lately I have been having headaches,extremely tired,constipation, more gasy(sorry)and very sore tender breasts, which I never ever have. Today what I thought was my period came, one day late(no big deal) but its very strange, i have very slight cramps, I am usually in agony, and brown discharge,very light amount of discharge too and when i wipe its brown. This has never happened as I usually get very heavy red flow but have never had anything like this. Please help im very confused. Thanks everyone