My nipples hate me..

For almost 2 weeks now my nipples have been tender. They've never been this tender before and they only feel this way when I'm about to start but I won't start till the 15th or 18th. My nipples are killing me. I took a pregnancy test a few days ago and it came back negative. I'm not having any noticeable signs of pregnancy except insomnia and weight gain but I get the munchies at night and ive been pretty sad this past month.

My SO did suck on them before they started hurting so maybe he sucked on them to hard? But it felt the same to me. I was very emotional the week prior but I'm not anymore. Any ideas ladies.