I had sex 4 days ago for the first time. i have been spotting blood and clear/yellowish discharge, including clots with the spotting. i have pcos.

Likely not STD: It would be too early for an STD to start. Could you have inadvertently left a tampon in before sex or possibly a condom? I realize this might seem absurd but it's more common than you would think in practice, therefore I wanted to mention in. I wouldn't be too concerned about the spotting and clots, that can be normal. Watch it for 1 more week and let us know.