Bleeding after sex 7 DPO

Adrienne • I`m 33 and trying for my second baby. I`m also incredibly impatient! We`ve had two chemical pregnancies in 6 months.
Okay so hubby and I bded tonight and afterwards I had bright pink blood! I figure I'm out again this month. I'm so frustrated. Slight cramping. Was not expecting AF this soon or any spotting for that matter this early. Anyone have any suggestions why this is happening.