Should I guard my heart?

So based on my LMP (January 5) I should be 8 weeks 4 days today. Last night I went to the walk in OB ER because I was spotting and cramping. The ER gave me an ultrasound and told me baby was measuring 6 weeks 2 days but had a heartbeat. I have two living kids that were small… my first born was born at 38 weeks and was only 5lbs and my second was born at 40 weeks and was only 7lbs exactly. Both boys. So I figure I just make small babies. I had some red spotting after the speculum/transvaginal ultrasound last night but it has eased up now and I feel fine. Should I still guard my heart? I have a follow up ultrasound tomorrow. I’m just wondering what to expect.