First day spotting second day light to medium with clots on the tissue and tampon third day light again had sex during ovulation is it pregnancy or me?

Check a test : If you think you might be pregnant check then check a home pregnancy test. They are cheap, reliable and available at any pharmacy. It is not clear exactly if you are bleeding at this time during your normal time or during an abnormal time. If you are experiencing abnormal bleeding consider seeing an Obgyn

When in doubt: just check pregnancy test in 2 weeks and repeat if negative in 1 week. And if you are still not bleeding normally and first pregnancy test was negative, check it again in 1 week. If negative then go see your GYN or family physician to get examined for infection if things persist.