Last Month I Had A Dark Only-light Flow Period. This

last month I had a dark only-light flow period. This month I had constipation for a few days, breast tenderness for two days, and now I am getting a light flow with bright red blood. I have taken three tests (one before my period, another a week after my period, and now, at 7 weeks) and all came back negative. is this normal or am I freaking out?