10 weeks and spotting

So I'm 10 weeks tomorrow with baby#2. I only spotted with my first baby right after sex and it only lasted a few minutes. I randomly started spotting bright red when I wipe today. I called my doctor and they said I was fine but to call back if it got worse or I started cramping. It stopped then started spotting pink. I haven't had sex in 2 days but they said maybe it was from that. Can I start spotting that long after sex?