Should I see the doctor

Theodora • TTC # 1 IVF 🙏 Unexplained infertility/endometriosis

My mother told me that for 3 months she was trying based on a doctor who told her she ovulated on the 20th which I already believe is very late but then she found out after not getting pregnant but she was do you tell if you late on the 23rd. I am so confused I think I should probably go to a doctor. But is there anyone who has been to a doctor to find out and is there anyway for them to confirm 100% you ovulation date?