Yep, I think it's totally normal to still have fluid there, especially as it's only been 4 weeks.
I have noticed on occasions before I get in the shower there'll be a tiny bit of fluid on my bra (probably from being cold after getting undressed and nipples contracting etc! Sorry if TMI!), and P weaned almost 3 months ago.
Not a leaking weirdo at all Maybe you were having subconscious baby thoughts and you had a letdown...?