EWCM but - OPK?

Suzi
So yesterday as my husband and I were getting ready to go the the Packer game lastnight, I quick ran to the bathroom and as I wiped I had a glob (sorry, TMI) of EWCM. Told my husband and we did a "quickie" before we had to leave but then I had a negitive OPK? Is it possible to still actually ovulate with still getting a negitive OPK?