3 days of spotting

I have been spotting for 3 days now. It seems that the spotting is more this morning. I had a couple of drops on my pad-which before I would only see blood when I’m wiping. It’s more a darker red to brownish color. I don’t have any other signs-no cramping. I did see my fertility doctor yesterday but she couldn’t see a heartbeat. She wasn’t overly worried because I’m only 5 weeks and some days (had my IUI on 3/26). Has anyone experienced this kind of spotting and it turned out ok? I know I don’t have a Choice but to wait. She doesn’t want to see me back unless I’m bleeding a lot. My next appointment is next week. I’m just so worried