Should I be concerned?

I just hit 5 weeks, and since we ate dinner I have been feeling off.  My husband wanted breakfast so I had a few pieces of well done bacon and a biscuit with a glass of orange juice.  Since dinner I've been having acid problems and burping but now I am laying here trying to sleep and I started having cramps in the center of my abdomen but low.  I am 36 and this is my first pregnancy.  I haven't had any real morning sickness yet.  I'm not bleeding or anything but this doesn't feel like typical gas either.  Should I be concerned or did my stomach just not like the food today?