Baby moving can anyone help me???

Graziella
I am 18 weeks and 3 days and I don't feel the baby moving yet, sometimes I think I may feel something but I am not sure because it doesn't feel like a big kick which I know it's not supposed to right now. This is my second pregnancy and I hear your supposed to feel it sooner than your first. I have a doc appointment Tuesday but I am starting to get worried. Should I be or not yet????