I had sex 2 weeks ago & now 3 days after period ended tiny blood clots the size of a dot came out & when i wipe there is light pink brown blood, help?

Unrelated: The spotting after your period is likely unrelated to the sex you had 2 weeks ago. If you had unprotected intercourse 2 weeks ago and then had a period, you're likely not pregnant. The fact that you had this breakthrough bleeding or residual period bleeding is unrelated. If you want to have more predictable cycles, a birth control pill can help with that as it will stop breakthrough bleeding.