Pregnant but bleeding

So I got a call from my doctor yesterday saying my icsi worked and I’m pregnant. I was so shocked since I’m bleeding and didn’t expect that at all. I told her I’m bleeding and she said it’s normal. But now it has turn into dark red blood instead of brown blood. I’m bleeding less that my usual period but the color of it scares me and makes me wonder if it’s a miscarriage ? Any similar experiences?