My sis in law is alive cuz her dads tube regrew after getting cut (she's a twin!) So anything is possible go to the doctor
I would check with your doctor. Could be menopause or you could be pregnant. I don't know how long ago your boyfriend had his vasectomy but they can reverse themselves after 7-10yrs.
I would definitely recommend going to the doctor.
Those aren't always accurate . check with your doctor .