It could be the intercourse you had the night before. Same thing happened to me when I was like 12 weeks.
Except there was blood everyyywhere. I bled all night and the next day.
I went to my doctor to get checked, and it was just the sex. Lol
If it's really concerning you.. id go to the er..
You may be miscarring but just pray and take it real easy for the next couple of weeks. Make your next appointment and ask about the cerival cerclage. that may help you keep your pregnancy longer. Ill pray for you and congrats to you and your husband