Measurements

Hi guys!!! I haven’t been on here for a while, but I’m pregnant with my 3rd!!! Recently I had an ultrasound and they said baby’s head is measuring small, so they did a repeat along with my anatomy scan, her head is still measuring smaller but only by 6 days, they are freaking me out wanting me to go to a bigger city hospital for another ultrasound and once I hit 24 weeks they said they were gonna start the “high risk” protocol with me which means I go twice a week until baby is delivered! I feel like 6 days is not something to be doing all of this about. I know my doctor knows what’s best but he told me everything looks perfect with her other than her head measuring a little behind. I must add my genetic testing came back negative for all that it test for. Any advice? Opinions? TIA!♥️