Can I Get Pregnant With Precum.? As My Bf Did

can i get pregnant with precum.? as my bf did urinated march 3rd morning and ejaculated a little very little of pre cum near my vagina. my period should start on 15th march but it started 5 days late i.e on 20th march and it is in a normal regular period color but its not that high moreover the last month of my periods are also low. i'm confused that am i pregnant or not