DS is 13 weeks old. I noticed today that on 3 or 4 occasions, he sounded as if he was choking or taking sharp intakes of breath (as if he was struggling to breathe). This is not during feeding or because he put something in his mouth. Seems to do it when quite content. He doesn't seem distressed afterwards. It worries me when he does this and I pick him him up and pat his back. Anyone experienced it? He likes to do his fake coughs and so I wonder if this is another variant.....