dont known kung sino yung daddy

hi po,i just need your insights po... di konpo alam kung sino yung daddy ng baby ko i had 2 person in contact po kasi.. possible daddy #1 dec. 13 when we had sex.. (one night stand lng po,single pa po ako nun.. possible daddy #2 dec. 20 and so on.. when we had sex (boyfriend ko na po ngayun. Problem here is that i dont know my firstday of last mens.. so meron lng po ako is yung ultra sound result. sept. 13 is the EDD ko po... i Am now 18 weeks and 2 days pregnant.... ngayon, i was bother po kung sino yung daddy ng baby ko :( please no hate lng po.. i had some research din po, and thru online calculation most possible dad will be daddy #2... sapat na kaya itong basihan para masabi ko na c daddy number 2 talaga daddy ng baby ko???