I'm a teen mom and i am 9w2d

my doctor told me i have no gym restrictions and that I need to run and work out... so today I did my final in gym and ran a 31 on the pacer. right after i had cramping that lasted about a minute or so then i felt light headed.. I still feel very light headed. I'm at the nurses office right now and she told me to lay down on my left side. .. but should call my doctor? I'm getting worried and I'm still very light headed.. I ate and drank tons of water already.