Not that many symptoms kinda scared

I’m supposed to be 8w5d and when I went to my last ultra sound I was measuring a week and 1 day behind and the baby’s heartbeat was 131 but I don’t really have any symptoms besides sore breasts cramping and some nausea which is really rare and I have lightheadedness and headaches are these normal symptoms or should I be worried..I was taking prenatal vitamins but they don’t make me feel god so I stopped could that affect the growth of my baby do I need to start back ?