Urge to express months after weaning. Only one breast

So I haven’t breastfed my daughter in about 4/5 months. My right breast was always the main producer. The milk duct under the nipple still hurts sometimes and I have to express milk. Is this normal? Not pregnant and on BC. Wondering if it’s maybe just the BC hormones irritating me (only on my second month). I don’t remember this with my son but I also was pregnant with my daughter when he was only 3 months. Being sick with her my milk dried up when he was just 6 months. Anyways just wanted to ask!!