Body leaking while feeding?

Sorry this is TMI and probably gross, but I've found that at least once a day when I'm done feeding my baby I will stand up and there will be a wet spot approximately the size of my palm where I've been sitting on my bed or couch or rocker. I'm 100% certain it's not urine, which leads me to assume it's my uterus/vagina leaking??? Is this normal? I've never heard of it.

I've only been breastfeeding for 3 months ( my first baby will be 3 months on the 2nd).