spotting

2 days ago I started spotting. I've already called my doctor and they say it is normal and that this happens. It's not a lot and it's brown in color. I had sex with my husband 3 days ago and the next day I had some pink blood when I wiped (tmi, I'm sorry). Since then it has just been brown and pretty light, hasn't gotten any heavier. Has anyone else experienced this? I'm trying not to worry but it's hard.