Would there be a chance to become pregnant?

I've been tracking my periods in two apps. Glow says tomorrow I ovulate another app says I ovulate on Thursday. Today I noticed I have thick white mucus discharge sorry TMI. My husband and I had sex saturday and he pulled out but did his deed all over my vagina and have heard that you can still get pregnant that way. We have a 3 year old daughter already but my husband is freaking out and thinks I'm going to become pregnant. ( he's leaving for a year deployment so he's kinda scared that I'm ganna be pregnant while he's gone but we both want another child) do you think I have a chance of becoming pregnant or no. Thanks in advance🙂