Oh, I had this! I was in my 20's but the same situation holds true most likely. I was diagnosed with two issues. The first thing they did was check me to see if I had a small benign and harmless tumor in my pituitary gland. That is not uncommon and can cause lactation in non pregnant women. (really more like nipple discharge as I couldn't feed a baby with it). I had an MRI. I did NOT have that tumor. So, then we looked at my hormones. I had two things going on. First, I was hypothyroid. I took no medication and that resolved on its own. I did take a low dose of an SSRI as I had mild depression with it as a symptom. My doctor suggested that this can be very interrelated. When I treated the depression, that perhaps helped the thyroid issue. But regardless, it got better. Very happy about that as I did not want life long thyroid medication. And my levels have been great ever since (over two decades later). The second issue and probably MOST related to the lactation was that I had a hormone imbalance. I was naturally producing too much estrogen. Hyperprolactemia is the technical name and this is a nice article to copy and paste to your browser that tells you all about it. https://www.hormone.org/diseases-and-conditions/hyperprolactinemia You should talk to your doctor. Rule out a pituitary tumor (again, harmless, don't be scared) and they get your thyroid and hormones checked. This should solve the issue.