Why does this happen to me 😩

So I went for my first ultrasound today about 2 hours ago and everything seemed fine my baby's heartbeat is 166 measuring at 8W 2D but just now I started bleeding. I've already had 3 miscarriages, why does this have to happen to me right when I thought everything was going fine. I don't even know what to think/do anymore, it's just too much already having to go through 3 miscarriages.