Worried about spotting

Bella

I had my first doctor visit today to comfirm my pregnancy. Yes in fact I am pregnant. Due date March 12th 2019. I spotted on Saturday and I'm spotting today as well. I have 3 older children, adults actually. I never experienced this with any of them before so unsure if I should be worried. The doctor said it happens but is sending me an OB for ultrasound to make sure baby is growing properly. Should I be worried or is this normal for my age?