On the 15th day of my cycle, my husband ejaculated on my vagina, what's the likelihood that i can be pregnant? can the sperm find its way inside?

Yes: While it is unlikely, there is a chance.

Yes, it can: We start counting cycles as the first day of the period is day #1. If you had vulvar exposure to semen on day #15 (ovulation day), there is a fair chance that that you could get pregnant. Although less likely than a full-on semen delivery inside, there is always the possibility with the amazing way our bodies are set up to make babies. If you don't want babies, then start birth control.