Not-so-good day

I woke up to blood this morning. It really scared me. I immediately woke Brant up. As I do each morning, I had just been thinking how thankful I was that we had come this far. Brant looked up possible causes while I got dressed. I was thinking I would go to work and call the doctor's office when they opened. I got dressed and while driving, decided to go straight to the doctor. I sometimes lead myself to believe that work is most important. I don't know if it is my profession or the way I was raised, but this has to stop. This pregnancy was not easy to come by and it is my TOP priority. I  sat in the hall outside the office until they opened. My doctor is still on vacation, so I saw a person I had never seen. First we heard the heartbeat with a Doppler machine, (RELIEF!) She examined me and told me we needed to do an ultrasound as soon as we can to figure out what was causing the bleeding.
I made an appointment for the u/s at 11. They didn't see me until 12:15. The ultrasound technician took a lot of time with me, really listened and took me on a "tour." He was able to find a dark place in my placenta that he called bruising, which was causing the blood. Usually something like this would happen if you ran into a wall or got hit with something pretty hard. I asked him if it was due to lifting something, he couldn't say. Sometimes is it just unexplained. I can't recall anything ramming into me. My students are constantly hugging me and their heads are at the right height for damage, but I do not recall any of them pounding into me or anything. He kept telling me bleeding is not normal in pregnancy and that I did the right thing to come in right away.
I was sent home and told to take it easy. What happens tomorrow? I can't rest at work. I work with children. I am constantly busy and in a state of go-go-go at work. I'm worried about that, but I'll do my best. Other women on different forums and sites have had this and been put on bed rest or modified bed rest. I don't want to be on bed rest, but if there is danger to the baby, I'll do anything I have to. I am passed the 12 week hurdle, (13 weeks, 6 days,) but this is a critical gestational age and definitely not out of the woods. 
The technician was not going to tell me anything about the sex of the baby. Then we had a conversation about my previous technician telling me what she thought and the MaterniT21 test telling me the opposite. After that conversation and a little looking around, he did confirm the sex. (The blood test was correct.)
Scary day, but at least I got to see that our baby is doing okay.
Praying for a healthy baby and pregnancy.