Just need a quick refresher course in All this.?

Ok I have have three children a set of twins 9 years ago and another child 8 years ago. So it has been a while. I was never sick at all with any of them. No pain No Morning Sickness no nothing, except that my hurt really really bad the first time and a little less pain the 2nd time. Now here is my Problem My last MP was on March 15 or around that date. My cycle is 30 days. Give or take a day or two. Now I still haven't started and I am having cramps on my right lower side. Thought that it was My MP coming on but still nothing. And my s hurt a little but I don't know. The only thing is I only had three times right after the March 15th one. Could I be having another child?