Spotting at 9 weeks.....scared

So I had my first OB appt on Thursday at 10:30am. She did a pelvic exam. 24 hours later On Friday I started having period-strength cramps that lasted for 30 mins after my husband and I were intimate. Then around 7p that night I started spotting and got light cramping. It is now Saturday morning and I'm still spotting the same as last night but I don't have cramps at the moment. I've very scared. The doctor on call said to only go to ER if I start filling a pad or have unbearable cramps and to just rest this weekend and get into my doctor on Monday. This is my second pregnancy and nothing like this ever happened to me before. I have to go all weekend not having any peace of mind or idea what is going on. Has anyone ever experienced this?