Pregnant from the pull out method?

Let me start by saying I know the pull out method isn't 100% but my husband and I use it. Saying that, my husband swears he pulls out on time which I think so too. But now I am having pregnancy symtpoms. Cramps, headaches, backaches and one day I wiped and saw a little pink tinge. We wouldn't be upset if we had another baby, but has anyone experienced getting pregnant when yet your husband pulled out on time?