I had this happen to me at 9 weeks PG with my daughter. Lots of red blood (no cramping though sorry) I was in hospital at the time (due to HG) so I told one of the midwives. She didnt seem fussed & told me to put a pad in my knickers & see how I go through the night. In the morning I checked & there didnt seem to be as much as I thought there would be, the midwife told me I could have an ultrasound to ease my mind if I liked but she was pretty positive all was ok.
Of course I took her up on the u/s & she took me straight around to get it done. There was DD with a nice strong heart beat & she is now an incredibly happy & healthy 4.5 yr old!

I have heard alot of stories of woman losing blood & all being ok.

I dont want to concern you anymore than you already are but I would get checked tomorrow because you're having the cramping.

Hoping & praying your bub is fine