Hi there
Is it only just happening? We got told around the 3 week mark they start to be awake more and become more unsettled, like a growth spurt, they sometimes call them wonder weeks. I had trouble with my son when he was around the 4 month mark, he would only sleep for 20 minutes, then be wide awake. The only thing that worked for me was wrapping him, once we mastered it! he hated it initially, he would sleep for 2 hours at a time.
Its hard in the beginning, but it does get better.
Good luck with him