abnormal and late menstral after unprotected sex???

? I am 21 and i already have three beautiful boys!!A 4 year old a 16 month old and a 4 month old.The last two years in a row,i have conceived in sept.I breastfeed and have breastfed all of my boys.last month(sept) i menstrated from the 5th till the 12th.me and my hubby do not use condoms he just pulls out.But on the 22nd of sept we were thinking of spliting and we were in the heat of the moment and got careless,twice.With all of my boys i had cecearian births and the last two pregnancys have bothered my scar tissue,like i get sharp,tearing,stabing pains without warning and at no specific time.With my last pregnancy i thought i was preg but didnt take a test,about 2 to 3 wks into it i started getting the pains in my vagina and abdomen,i got scared and went to the ER thinking of miscarriage.they gave me a preg test and it was negative.they treated me for PID saying my uterus was in fact swollen.A week later the PID test showed negative,but preg tests were still negative too.finally around 2 1/2 months into the preg i tested positive on a home preg test.i really was prenant!!!!Anyway the problem is that we havent used protection of any kind and i started bleeding three days ago the morning after a night of somewhat painful sex.Not my usual menstral,one minute its kinda brown or watery and red plus its so lite i barely needed a panty liner per day.So we had unprotected sex last night and today i bled small gushes of maroon watery blood.i have all the pains i had with my last two pregnancys plus ive felt nausiated and overly tired,moody and very sensitively emotional.Am i preg or not and if so is the bleeding normal or a problem sign??????Help ????? :$ :-( o.O :'(