Period, when will it start again ?

So I gave birth 5 months ago and for the first 3 months id get my period every 2 weeks n now I don't even get it on the 4th month I got it out like spotting that's all n now ( the 5th month ) I haven't gotten it . Yes I did have sexual intercorse with condom but just sometimes with out it , would use pull out method ( not trying to get pregnant tho ) anyways n today we did it twice with condom first n then 4 hours later with out one can I get pregnant from pre cum ? How do we know what pre cum is ? I never understood that 😓 help lady's !!