Started having sex with an ex he put his penis in without a condom for maybe 5 minutes... Then we finished with a condom.. Had unprotected sex with my guy maybe 6 times in a two week period I'm pregnant and freaking out I know it's my guys baby but will Im scared it could be my ex baby

No way to tell without a DNA test of all concerned.

Whoever you had sex with since your last period could be the father. As noted, the only way to tell for sure is with a DNA test after birth.