It doesn't mean anything, OP.
When I fell pregnant with my oldest son I had the weirdest, most vivid dreams ever. I dreamt of being pregnant, lying on my in-laws chaise lounge eating grapes and wearing floaty dresses (just like a renaissance painting)
It was so REAL I HAD to do a pregnancy test to make sure.
So yes, I do think there is sometimes chemicals in the brain that do convert to dreams.
OK, but I've had many, many dreams over the years about being pregnant or giving birth and I've never been pregnant in my life.
I've also dreamt that I had a baby that turned out to be made out of orange plasticine, so yeah, I don't think that's chemicals in my brain reflecting reality somehow.
Also, the chemicals in the brain realised by sexual desire are the same regardless of the object of that desire, so even if it was brain chemistry that caused the OP to have this particular dream, all that would mean is that there were some sex/romance hormones drifting around in her body. It wouldn't mean that she secretly fancies the person she dreamt about.
It's completely normal to have sexual or romantic dreams about people you don't find in the slightest bit attractive in real life. It means nothing.