Yeah they can keep having babies multiple batches in a row even after being away from a male. Its pretty fascinating, and very unexpected if you arent aware of the fact.
(I saw a petstore worker advising someone to buy either only males or only females if they didnt want babies, but nooo just go males if you dont want babies lol i said nothing, theyd figure it out)
I had 5 batches of babies from a female platy who was not housed with a male for those 5 months.
Mark which day she had babies this time, around the same time next month you may see more