Im 28 weeks without the knowledge of my baby's sex, what is my baby's sex?

Have you asked your doctor when he/she has done an ultrasound?

Honestly, I have no way of knowing without an ultrasound or an amniocentesis.

You can always use the chinese gender predictor I mean it just for fun but hey I tried it with my last 2 pregnancy and it predicted them right

Only the result of a scan can tell you that, we have no way of knowing.