To early to feel like this??

Been feeling extremely exhausted lately. I can barely carry my 1yo son and walk at a snail speed to keep from having to stop to catch my breath and let my heart stop racing. I make it up a few steps then stop to rest before going up some more. I didn't experience this during my last pregnancy at all. During my last pregnancy I was chasing our pigs and doing normal daily activities with ease. I know every pregnancy is different but this just feels a bit off. I'm only 19 weeks along. I could totally understand if I was nearing delivery but I've got a long way to go. Any suggestions or personal experiences that might help me get through this?