Bleeding after sex 33 weeks 4 days

So I've read that it's fairly common to have some spotting after sex but this is the first time it's happened to me and this is baby #5. Fiancé and I had sex around 11 am and I'm still noticing it now 6 hrs later. It's more of a pinkish/brown color and not too much in quantity. I just feel a lot of pressure down there and very very sore. I've had a lot of Braxton Hicks the last few days prior to this as well as loose stools. Wondering if the blood is from the sex or the start of preterm labor, I have felt sooo OFF the last 2 days, like something is just weird and not quite right. Baby girl is still active....

Any thoughts or advice?