screening tests

Has anybody experienced a false positive AFP (alpha-fetoprotien) screening? I've read online it's notorious for false positives but I just wanted some insight from you ladies. I recently had to get my blood drawn for a 2 part blood test and an ultrasound. I got a call back from genetics saying that I screened negative for Downs and trisomy18 but my AFP was slightly raised so they're moving my 20 week anatomy scan to 18 weeks so they can do further testing and see if there's a neural tube defect. Obviously when I was told this news my first reaction was "there's something wrong with my baby" but after some research(surprisingly) that put my mind at ease a little bit for the screening to just be a false positive since those seem to be pretty common. Has anybody else experienced this? If so please leave a comment about your story because I'm very interested on how things turned out for you. Prayers and good vibes are welcomed here💕 Thank you in advance.