Anyone else riddled with anxiety about miscarriage?

Since finding out I was pregnant, I've had this constant fear I'm going to miscarry or have an ectopic pregnancy, or something is going to go wrong. I don't know how to shake this fear. I have a healthy 18 month old little girl, and I don't remember having this level of anxiety with my first. In my head I'm telling myself it's because my gut knows something is off. Last month I had what the doctor thinks was a chemical, however I think it was faulty tests because the positive tests, although multiple of them were spread over 8 days, with negatives in between, which to me doesn't seem like a chemical. I went to the doctor because I had sharp pains on my right side, and had a couple of random pregnancy tests, and someone advised me it could be an ectopic pregnancy. I believe I could have cystic ovaries causing the pain though, as I struggle to ovulate more than about twice a year, despite regular periods. But I don't know if the doctors telling me this has put the fear of God up me. I also had pre eclampsia with my first, and I am terrified of having this again, both because the birth was awful, and because my partner and I have agreed if I am to get pregnant eclampsia again, this will be our last baby. I want 4 children, so this will break my heart, even though I know it would be the sensible decision. Sorry for the long post, I just needed to get it off my chest and see if others are also stressed to the max.