BREASTFEEDING HELP

My son is not quite 36hrs old, I have very little colostrum. He has been nursing for nearly an hour straight, if I pull away he is almost panicky looking to latch back on. Should I definitely be hearing an audible swallow while hes nursing? Or not yet until I get milk in? He will suck and then pause and repeat, but I'm not convinced hes getting anything and I'm starting to worry.

Is he maybe just "cluster feeding" or just using me as comfort and not really eating?