Bleeding

I am five weeks and three days today. At work I went to use the bathroom and went to wipe and saw blood (not brown like I had been having) and then looked in the toilet and I could see it in there too. I panicked and called my OB. She wanted me to relax and go home and drink some water. Then thirty minutes later she calls me and says she wants to do blood testing and I go in quickly and they take blood and that’s about it. I am trying not to stress out but I can’t help it. I have pretty bad lower back pain and sometimes intense cramps. 😢 this is my first pregnancy...