OPK vs BBT

Mikaela

Hey everyone! Quick question, so I’ve just recently starting tracking my BBT for the past couple cycles along with using OPKs. I was just curious which test is more accurate in order to time intercourse? For example, my last cycle I got a peak OPK on CD 15, but then my BBT showed I ovulated on CD 18. Should I base my ovulation off BBT results instead of OPKs?