Can’t stop worrying about another miscarriage

Ive had 2 miscarriages first one at 6 weeks and the second at 5 weeks. I’m now pregnant again and based on my last missed period I thought I was 7 weeks...went for scan and I was measuring at 5w6d they could only see a sac and what they think is a heart. Told me to go back in two weeks to make sure the pregnancy is still progressing. After the scan I had some brownish discharge which I know can be normal but also had severe cramps similar to my first miscarriage. I haven’t had any bleeding but during my first miscarriage I had bad cramping days before I ever saw blood. I’m just really worried we really wanted this baby to stick and I just feel so hopeless right now...