Sex & pregnacy‼️‼️

Ha
My boyfriend and i have sex quite often. The very last time we done it was unprotected. He didnt cum and said he didng even come close to cumming. He also "milked" his dick before. Like got all the precum out but im still worried. Normally he doesnt have much precum at all and when he cums its not a lot but its judt the chance of what if some precum got in me and i could be pregnant. What are the chances???