Terrified of a miscarriage

Okay little background....had a chemical. November 2017. Ectopic February 2018. Never once had a successful pregnancy.

Have been on birth control since March. Missed my period last week so Tuesday took a test just to check and came back very positive. Doctors told me the next time I get pregnant to call to come in right away with my history. Went in on Wednesday. Had an ultrasound where they were able to confirm the baby was in the right spot. Heartbeat of 111 and I was 5w 5d. (6 weeks today.) HCG came back at like 1600. Also had a pap.

Have been feeling great about everything. Today out of no where i start panicking about a miscarriage. Constantly checking when I pee. To the point of checking on cervix for blood which I found a little bit and absolutely freaked out. Doctor told me the pap could cause spotting but in the back of my head I’m feeling deja vu. I want this to be successful so damn bad. But I can’t even enjoy the thought of being pregnant because I’m terrified of a miscarriage. From what I’ve read after the heartbeat is found the chances of a miscarriage are very low but I can’t calm down. Anyone else the same way?