you may want to call your doc. I had the same at 19.5 weeks and it was bright red. I called the doc and they said as long as it was just spotting or staining and not a flow, it is normal. they did not even have me come in. Like I said, I would call to be on the safe side, but it is probably nothing.
Definitely call your dr. It could be nothing...but when it happened to me , it turned out to be serious...
Call your doctor. Always let them decide what's important, and what's not.
Good luck. Keep us posted.