Is it possible to get pregnant from precum? i ended up pregnant but there was no ejaculation at all.

Yes it: is possible that there are viable sperm in the pre ejaculate.

Potentially: Most older studies have shown low levels of sperm or no sperm in pre-ejaculate with sperm not being motile (however, don't know how promptly samples were examined). A study published in 2011 showed that there are some individuals with a high motile sperm count in pre-ejaculate. See: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3564677/