TMI - Spotting

Rebecca
Hi guys, wanted some advice as haven't been able to see my doctor yet.
After having sex I got some spotting which I didn't even know was there till I went to the loo. Obviously worried next day took a preg test and still pregnant with a darker line that originally. 
Had another occurrence of very light pink spotting on wiping after sex.
I've read that you can get bleeding after sex due to increased blood flow to the cervix. Has anyone else experience this and had a normal pregnancy? My libido recent had dropped though the floor so didn't know if that had anything to do with it. Due to see dr next week. Currently 7+1.