lol no. Even with precum it's a lot less likely to get pregnant. Women try for months even years to get pregnant. I've heard precum is fertile but at a very low rate. His sperm would have to have contact with your fertile egg and implant inside your uterus.
a) Precum oozes out at body temperature, it's not like it feels noticeable.
b) It's not the easiest way to get pregnant, but you could get pregnant grinding naked against a guy's erect penis.
It is not too late to take Plan B, but you should move fast. I think 72 hours is the outside timeline.
ps -- If you are going to get together naked and don't want to be pregnant, please get on the pill. This time, next time or the time after, if you push the envelope like this, something will happen.