So confused

Danielle

Going from my lmp the app is saying i am 16 weeks but according to my scan i am 17 weeks. If i go by my scan it means i concieved 10 after the first day of my last period but i wasnt due to ovulate for about another week and a half. Last period was 16th october my app said i would ovulate about the 30th i am so so so confused right now