6 weeks pregnant, cramping and light spotting?

So i dont often post publicy about anything private but i am too worried not to! after a previous miscarriage 6 months ago and endometriosis surgery, i am super afraid to suffer the same heartbreak. I am just over 6 weeks pregnant, i had sex last night, felt alot of cramping and aches this morning followed by some light pink spotting? It has now calmed down, but i am now super nervous as i am still experiencing back ache snd cramping is mildly continuing. Any reassurance would be much appreciate!!