My phone keeps vibrating at random times
So I recently updated it and ever since then my phone (iPhone 4s) and right when I plug it in and it gets to 80% charge. It starts vibrating at random intervals. I think It might e the charger. I don't have an iPhone wall plug-in, but I have used this before and it worked perfectly. Now it's just screwing up, and I can't sleep because I'm scared my phone will either break/mess up. It also vibrates pretty loudly.