My boyfriend and I were hugging in only our underwears but I felt him wet with precum (no semen). I let go of him immediately, but will I get pregnant?

No. not if if it only touched your underwear.
Here are some... Considering the high fastidious requirements for sperms to survive, move, & swim to fertilize a timely waiting egg at right site & environment, the reported scenario poses a next to zero odd to conceive. Nonetheless, still do HPT in a wk after missing period & repeat it in another wk if the first test is (-) & still in doubt. More? Ask...