everyone, pls help answer my H4-F1-485, Thanks!

My status was H4, then F1 until graduation this May. I forgot to transfer back to H4. But my 485 is pending and I have EAD.
- Am I illegal staying in US now?
- If I want to go back to University this Fall, can I? Back on F1 or EAD allows me to do so?

Thanks again!