This is extremely random I know....

My period is due in 3 days and the last couple of days I have felt different and my breast are very swollen, I went to take my bra off and both my nipples were stuck to my bra 😮 I have 2 children from a previous relationship and breast fed both. My youngest is 5 almost 6 and I’ve never had this before? There were wet circles in my bra where obviously they have leaked. Has anyone ever had this before and what was the cause?