I am worried.

I went to my 12 week scan and I found out that my baby nt was 2.6 and it was normal but they said it was close to higher side of normal instead of leaving it they thought they should do more they took blood test and my test came back it was fine and I was a low risk for Down syndrome it was 1 in 2,500 risk of trisomy is in 18 less than 1 in 50,000 risk of trisomy 13 1 in 12,000 which At 21 was okay to them but I was still worried and I was told I would see a specialist when I went to see the specialist everything was normal but she was a little worried about one side of the brain she said it was normal but she wanted to see if anything would change or if the fluid in their brain would get larger I am now starting to think I should do go-ahead and do other tests yo know what my child will have and will have a better chance of knowing what to do at I’ at 21 was okay to them but I was still worried and I was told I would see a specialist when I went to see the specialist everything was normal but she was a little worried about one side of the brain she said it was normal but she wanted to see if anything would change or if the fluid in their brain would get larger I am now starting to think I should do go ahead and do other test to know what my child will have and will have a better chance of knowing what to do but I’m also Single mum I’m not having anything to do with that dad . Told me I would be able to do nipt and invasive test but comes with 1% chance of miscarriage what would you do