C.H.
Congratulations! I echo a lot of other posters. Keep breastfeeding and see if it improves. If not, I would strongly suspect a food sensitivity (my son has several - he is 21 months and still breastfeeding a few times a day). Dairy is a usual suspect, although my son also has issues with corn. He used to cry at the breast and spit up a ton if I ate corn products. Once I eliminated dairy and corn, he stopped spitting up and fed quite happily.
good luck!!