Could i be pregnant again after having second baby 8 weeks ago? x thanks?

hey everyone.....right i had a baby my 2nd 8 weeks ago saturday.....i stopped bleeding quite early on and had my very first period on the 9th june ( had been spotting for 4 days before).....only the friday was heavy flow and came off sunday morning so was on for 4 days........me n my husband had unprotected sex on the 18th june ( 6 days after my period) and straight away that day i started spotting and stayed spotting also was watery....but no red blood...only spotting for 3 days then stopped also had cramping with it only slight nothing painful....have been getting really bad headaches now.....we are only using condoms until i see doctor in 2 weeks.....but wot are my chances of ovulating 6 odd days after my period and getting pregnant?...also could that bleed be implantation bleeding?.....when could i test due to not knowing wen my next period would be? xx thanks alot xx