Hi Ladies, Could you please please help me.

Ok just trying to work out ovulation here.

Sunday CD15 i got a negative on the OPK. Temp = 36.7
Monday CD16 Morning, got a negative, as the test line was slighty lighter then control line. Temp = 36.6. Then 12hrs later that night, i got a + as both lines where same colour.
Tuesday CD17 + on OPK. The test line was darker then the control line. Ok my temp rised to 37.5.

So does that mean i ovulated today, being tuesday, or yesterday???? I would love some help, as it honestly sends me nutters!!!