I can feel baby, but not as strongly as before. Should I be concerned?

I'm 28 weeks pregnant with my 3rd baby. I can still feel him moving but I've definitely noticed that his kicks aren't as strong as they have been before. Should this be a concern? I have anterior placenta which I never had with my last 2. I felt every little punch with them pretty early on and didn't feel this baby until much later on. When I do feel him it's mostly on my sides, which I'm assuming is because the placement of the placenta. I really don't want to be a hypochondriac but is this something I should be concerned about? I've felt at least 10 small movements in this past hour they're just not strong movements. I'm definitely feeling a little anxious about it because like I said I don't want to be a hypochondriac but I also don't want to brush it off completely and something actually be wrong. I plan on calling my ob when they open but it's currently 4 in the morning right now.