Bleeding at 13 weeks but baby is fine

At 12 weeks 6 days I randomly experienced a “gush” of bright red blood whole eating dinner and was sure that I must’ve been having a miscarriage but the bleeding stopped quickly and was completely gone by morning. I went to the ER the next day and the baby was perfectly fine, moving around with a strong heart beat on the ultrasound and my cervix was still closed (which is good!). My OB said sometimes you just bleed for random reasons during pregnancy and that as long as you can see the baby on the ultrasound and see the heart rate that it’s not really a cause for concern. Anyone have a similar experience with bleeding?