Hi, I Am 28 Yrs Old. Trying For Pregnancy. Last

Hi, I am 28 yrs old. Trying for pregnancy. Last month was our first attempt and we tried during my fertile period supposedly.The day we tried i started to have cramps in my lower abdomen on 1 side. Later started feeling nauseaous, sleepy etc. If i talk about my periods it always occurs one day before the due date.I was having few symptoms of pregnancy i suppose which has not happened to me ever between the last period and the coming period. I assumed that i might be pregnant so i started taking folic acid tablet. This month my periods got 2 days late that is on 24 march,2016 in afternoon. The initial discharge was brown in color but later it turned red. And generally my periods stay for 5 to 6 days with 3 days heavy to medium bleeding. But this time first day it was more but from 2nd day itself it got light and now today its almost like over. Can u please help me with circumstance as to what could it be..??(Urgently)