Brown Spotting

My first pregnancy ended in a missed miscarriage at 17 weeks. My baby measured at 13 weeks which meant that i had carried it for 4 weeks without any indication that anything was wrong. I only found out due to an ultrasound at a regular prenatal checkup. I didn't even start "bleeding" until 2 days after i found out, which was really only brown discharge that i believe was brought on by my stress levels since i had been crying for 2 days straight. I ended up having a complete D&C; without any complications and got my period a month later with normal cycles after that (no issues ovulating, no late periods, no irregular flow).

4 Months later, i am 6w4d pregnant with my second. I found out i was pregnant at 4w5d via blood test. 3 days later, i noticed a tiny amount of brown discharge when i wiped. Obviously, alarmed, i immediately contacted the OBGYN clinic at my hospital and they recommended me go get checked out at the ER given how my last pregnancy ended.

They ran another blood test to check my quant levels, did a pelvic exam to check my cervix (they said if it is opened, it indicates a miscarriage) and to check for infection, and an ultrasound to see where the pregnancy was. My quant levels went from around 400 on Friday (the day i found out i was pregnant) to almost 1200 on Tuesday. They say that your levels should double every 48-96 hours to indicate a healthy pregnancy. My cervix was closed and the tests they ran for an infection came back negative. The ultrasound found a gestastional sac with a fetal pole in the uterus, which ruled out a molar and ectopic pregnancy. They told me that everything looked good and would indicate the beginning of a healthy pregnancy, other than the spotting but that apparently, brown discharge and spotting is quite normal during the first trimester. Heck, my sister in law had "period like" bleeding for the first three months of her pregnancy and her baby is almost 3!

I was obviously relieved and figured the spotting would stop but it is currently 1 week and 3 days later and i'm still experiencing the same brown spotting with occasional stringy like clots. The spotting is fairly light, doesn't come out at night, and doesn't even require a panty liner. There are a couple of times during the day where there is enough to where i can actually feel it come out (similar to menstrual bleeding, not prompted from wiping), but it's only a drop or two. The blood has never changed colors, which would be indicative there is no active bleeding. I'm only having occasional cramps that are light and intermittent. I'm still getting nauseous and experiencing pregnancy symptoms daily. I don't have my follow up ultrasound for another week, which means 1 more week of worrying and googling. Has this ever happened to anyone else?

1. Brown blood is an indication of old blood. Where is my old blood coming from if my cervix is closed? And if i had, indeed, miscarried, wouldn't that mean that i miscarried way before i started spotting? It doesn't make sense because my quant levels were increasing the way they should on the day it started happening.

2. My husband and i haven't had intercourse since it happened and i havent stuck anything up there (tampons, period cups, toys, etc). My husband and i had intercourse two days before the spotting started, and they did irritate the cervix during the ultrasound and pelvic exam but i wouldn't think it would be bleeding over a week later.