PJiang, Please another question about H4->F1.

I have the H4 Status. I got the Graduate Assistantship and will work 20 hours every week. I ask all the teachers and may transfer my H4 to F1 firstly.
- Yes, if you have not started immigration petition. ::??

My hu*****and submitted the I-140 but his PD (sept,07) is far away from current date of I-485. Does it affect my transfer from H4 to F1??? Thank you very much!!!