I have seen some similar posts, but wanted to tell my particular story in the hopes I will find an answer! (I am sorry this is so long)
My now-13 week old has always nursed very well. She has also always been very happy and she never continued to cry when offered the breast. Well, two and a half weeks ago she started crying one evening and I couldn't get her to quiet down for over an hour! It was very unusual behavior for her. She wouldn't drink, just cried and cried. I was starting to think something was seriously wrong, when she finally had a decent feeding and fell asleep.
After that, she was very fussy. I couldn't put her down during the day without her immediately starting to cry. And the crying got intense very quickly. If I didn't pick her up right away she would start screaming. Again, this was very unusual behavior for her. At feedings, she would latch on, take a drink or two, then fling her arm back and unlatch. Then she would immediately seek the nipple and latch back on. This would happen over and over again.
Fast forward two weeks. I took her to the doctor the day before Thanksgiving, because I thought she might have a UTI (my first daughter had urinary reflux and I was told it was hereditary), but the urine culture came back normal. Ears were fine, chest was fine. Everyone else in the family had a bad cold, so that was my second guess, but she wasn't sick.
The crying when I put her down has improved greatly, but she is still really fussy at mealtime. She weighs 14lbs 9oz. She latches and unlatches repeatedly, but I *know* she's hungry (I think I know, anyway) and if I take the breast away (thinking she must not be hungry after all) she gets upset.
She has been drooling a lot. I'm wondering if it is teething pain? The doc said it's too early for that, but I realize they don't know everything!
It has never occurred to me that I had a fast let-down -- I've never seen any other signs. Occasionally she does choke/cough while nursing, but I assumed that all babies do at some point. ??
I hope someone can help!