I have irregular periods. They usually last 8 to 9 days and the last few days is brown spotting, old blood I'm assuming. On the last day of my period this month my parter and I were "dry humping" in our underwear and things got a little out of hand. He was pressing the tip of his penis to the opening of my vagina, but we both still had our underwear on. He ejaculated on my underwear. Could this lead to pregnancy? I know this question may seem silly but I have read so many different opinions on if this could lead to pregnancy, and since my periods are irregular it's difficult to gauge when I may be ovulating. Thank you in advance for the help.