HELP?!

Chloe🦄✨

Do you go from your LMP or the date from your scans???

21st Jan, BPF was 21st February, according to my due date (10th November) I was supposed to ovulate 17th February, but from my LMP it was supposed to be February 4thish, so would I go from my LMP or scans as LMP is 34+3 and scans is 32+3? But if I go from scans then it would have been impossible to get my BPF on the 21st (missed period was 18th so a day after I was supposed to ovulate)???