I haven't been working out much for quite a while and a week ago I started a new workout program and have been working out every day. Two nights ago I blew my nose and felt a strange isolated pain in my upper left ab muscle about 2 inches below my rib cage. It's been two days now and the pain comes and goes but when it does hurt it feels like I'm being pinched in that one spot. I thought I felt a small bump in my muscle about the size of a small pebble. Could this be a hernia from working out?