My baby's head is small?

This is pretty long, bare with me lol

So I'm paranoid as hell. I had an appointment for ultrasound at 31 weeks and was told that they were referring me to a perinatal doctor because her head was measuring a bit small. So I went to that appointment at 34 weeks and the doctor there told us that if there were 100 babies measured at 34 weeks, mine has the smallest head. But nobody has told me exactly how small it is. They said her body and everything else about her is perfect but her head is little. My parents said that my whole family has always had smaller heads and been fine but I can't help but be terrified for my little girl. They talked about possible viruses that I could have come in contact with, but I looked at what they tested for and none of them sounded like anything I've contacted. Zika isn't an issue for me either. We also tested for trisomy 21, 13 and 18 and I did an mri a couple days ago to get a good look at her brain to make sure that things look like they are where they should be and everything.. I had my first blood test for trisomy at 34 weeks and the other for viruses about a week ago. I'm 36 weeks now and haven't heard anything about any results yet which is very frustrating.

Does anyone else have any experience with this??? Being told their baby has a small head ? What was the end results for you? I of course will love my girl no matter what. ..I'm just so afraid that something will be wrong. I'm most afraid that she will have trisomy 18 or 13 because I know babies don't survive that. My doctor wants to induce and get her out at 39 weeks and I have ultrasounds once a week and non stress tests twice a week on top of regular ob appointments. I'm always on the go with doctor appointments and it's really starting to wear me down. It's so hard to always stay positive around family and friends about all of this when all I really want to do is crawl in my bed and cry. I'm worried all of the time for her. It's just not fair and I know that life isn't fair.. but I have to wonder why me. Why us. We tried for four years to finally get pregnant and now at the very end of my pregnancy..something isn't right 😳😢

I need to hear that others have experienced this before and things have been okay.

any experience with this would be nice to hear about.. so i can at least not feel so alone about it.