Joining University on H4

[Sweety3]

HI,

Currently, I am holding H4 Visa and it is getting expired in Aug 2018. I am planning to join masters in US near to my area of residence on H4 visa and later convert it to F1 visa. I already got an admit from university and the classes start on September end 2018 for the fall Quarter. By September, my husband’s visa will be in extension process but won’t be able to get result by then. Am I still eligible to join the university with H4 status as H1 extension will be in process. Will this extension process cause any effect for getting my F1 visa stamped at a later time may be in October or November? Also, to be eligible for CPT or OPT, do I need to be on F1 Visa for a particular period of time?

Thanks in advance.