So I went to the doctor and he told me I was 7 weeks and 2 days. But my app said 7 weeks 6 day. My…

So I went to the doctor and he told me I was 7 weeks and 2 days. But my app said 7 weeks 6 day. My period was July 1-5 and I got a positive ovulation test on the 21-22. So is he right? He based it off of the size of the baby. My husband and I are not kinda short so Idk if that has anything to do with it.