ANSWER:

If you are a female, no problem in praying on your own even if the jamah starts because its not mandatory on women to pray in the masjid in congregation. 

QUESTION: At school, I don’t have the space to pray.So I go to the nearest mosque on my lunch break to pray dhuhr as soon as it starts.But I don’t have the time to wait for the jama’a as I’d miss my next class, so I pray seperately, on my own. Sometimes the jama’ah starts while I’m still praying on my own, is it permissible to continue praying? I also don’t know how to pray in congregation correctly yet