Gasping for air.. ??

Aftin • Baby #1 born 4/6/16, TTC #2 (hoping for a girl 💜)
My son is almost 5m old now. When he was a newborn he would gasp for air while soundly sleeping. Our DR said it was normal and its part of the lungs developing. He continued to do it almost daily, but We moved him from bassinet to crib about 4 weeks ago now, so I don't hear it in his sleep since he isn't next to me. Recently he started doing it during the day too. It's like a strangulation gasp, it sounds serious! He does it while relaxing, and while cranky when it's nap time... So it's a sparatic occurrence on all of his different moods. I was wondering if any of you experienced this. Should I bring him back to dr and make them really look into it? I have videos. I saw other moms post videos on YouTube but there were no answers to read with the post. Thanks!!