The first time i had sex with someone else was on february 23rd which test is saying that's my conception date but me & my ex would hang out with me often having sex also we tried for a baby before a baby for a year before we broke up. who's the dad?

The only worthwhile answer & one that will hold up in court proceedings will be a DNA based paternity test. The NIPP is a non-invasive test performed on your blood as early as 8 weeks. They find fetal DNA in your blood & can test it for a variety of things including paternity. Ultrasounds and projected dates can give data, but a surprise at delivery is not worth a wrong call.