Lower back pain and some cramps

So last week, while I was sick, I was worried that my pregnancy symptoms were decreasing and that the baby was no longer alive. Now that the cold/flu is gone, I noticed the symptoms are still there, but get freaked out because yesterday evening I suddenly got some cramps and lower back pain and I'm worried I'm going to have a miscarriage. It came back early this morning and this afternoon around 4 pm (still there while I write this). Absolutely no bleeding or spotting though, just some mild pain, like when you have your period - around day 3, nothing like the horrible cramps I usually have on day 1 and 2. So I assume/hope it's normal, due to the uterus expanding or something, but of course I keep a check on it to see if it gets any worse.