Thank you all so much. I went to my OB/GYN and she did a breast exam and all that. She said everything feels normal and that she didn't think it was anything to worry about. However, I saw a different dr. than my regular and she asked me if I ever have headaches or vision changes because one reason this can happen is small tumors in the brain near the pituitary gland. Uhhh, not something I needed to hear right now.
BUT, I don't have any of those things and she said she doesn't think this is anything to worry. She said if it were cancer or an infection, the discharge would be green or bloody and that the milky color I described was very reassuring.
So I guess I feel a lot better than I did but am still kind of worried :-\ I really want to believe her that it's probably fine but I keep thinking, what if it's not?
EDIT: She also said that hormone fluctuations could cause this. Also, that if it only happens when I squeeze or stimulate the breast in some way, it's not concerning. If it starts happening without doing that, she'd send me for an ultrasound. Hoping it won't come to that! The first time it happened this morning, it came out pretty easily when I barely squeezed it. Now, it seems I have to really squeeze to get anything out. So maybe it was just a fluke thing?