I am wondering about the possibility of being pregnant.I had intercourse on 4/18, and started bleeding on 4/19, and went to the OBGYN on 4/20 and received neg urine and blood test.However, the bleeding I had was late for my usual period, was very light and only lasted about 3 days...not at all typical for me.Since then I have been experiencing headaches, breast and nipple soreness, low appetite, nausea, mild cramping, and today (10 days since unprotected sex) I have some spotting and discharge. I am wondering if it s possible I am pregnant and experiencing implantation bleeding today? Would it be possible?