Is this normal at this stage in pregnancy?

Well, I am 37 weeks pregnant with my third child, I will be 38 weeks on Tuesday,but for some reason, my son has not dropped at all. With my first pregnancy,she didn't show any signs of coming, but did a c-section 5 days before my due date due to severe preeclampsia. With my second child, I felt completely normal one day and the next day, I woke up to find that my water had broken and that was 8 days before the due date. Now, I just had my prenatal checkup two days ago, and the doctor said that my cervix is still closed. Should I be worried, considering that this is my third pregnancy? Has this happened to anyone?