Confused

Sooo... My husband and I have been trying to conceive since January, with heartbreak after heartbreak...
For the last week I've had light annoying cramping. I am three days late, had a negative pregnancy test but today when I went to the bathroom there was light very little pink blood on the toilet paper. That happened only once today... Every other time there's been no blood.  I'm sick to my stomach and fee like I'm getting my hopes up.
Any advice? What are the chances I could be pregnant and the rest was too soon? What are the ha cea I'm about to start? :(