I was the same as you. I have felt baby since about 14 weeks. At 17 weeks she completely stopped. I didn't feel anything. Then at 18 weeks i started seeing her kicks on my belly and now she won't stop. Your baby might have shifted further towards your back for a bit. Try not to worry unless your cramps are unbearable or you start bleeding. :) Good luck to you and your little one!
If you've gone from feeling him often to feeling him often to not feeling him at all do for more than a day, you should go to the ER.
I'm 24 weeks 3 days, she didn't kick for four days and now she won't stop. From what the dr told me it's normal up until you hit 28 weeks. Then obviously if they don't kick a certain amount of times in an hour you need to go in. Hope I helped a little?