Probability of pregnancy. lmp 07/09/14, unprotected sex 07/18 (twice), 07/19 late at night. positive opk 07/22?

Pregnant?: There is certainly a possibility, but possibly not terribly high. Here's why: OPK turned positive about 3 days after last intercourse. OPK turns positive 1 to 2 days before ovulation. Sperm typically survive for NMT 3 days after ejaculation. By these numbers there is a gap of at least a day. Admittedly thin ice, but it might be enough. Do a HPT if your period is late.