HELP NEED ANSWERS...CAN I BE?

OK A YEAR AGO I CAME TO EVERYONE WITH THE SAME QUESTION CAN YOU GET PREGGO 2 OR 3 DAYS AFTER YOUR PERIOD??? LAST YEAR THIS TIME MOST TOLD ME NO ....TO FIND OUT I WAS...... AND ENDED UP HAVING A MISCARRIAGE WKS LATER ...... :( BUT NOW...I noticed my period moved from the 22nd to the 1st of every mth. ok...MY PERIOD CAME ON THE 31ST TO THE 4TH I had on the 6th of feb which was my bday and the 7th in the morning. I ALSO HAD ON THE 27TH AND IN THE MORNING ON THE 28TH.... I AM 30 YRS OLD WITH A 9 YEAR OLD BOY AND I WANT A GIRL NOW IT GOD ALLOWS IT.... COULD I BE ????? I TOOK A TEST THIS MORNING NEGATIVE ... SAME AS LAST TIME......IS IT TO EARLY FOR THE TEST????? MY PERIODS 3 OR 2 DAYS LATE I FEEL CRAMPS JUST LIKE LAST YEARS QUESTION.... HOW DOES THE OVULATION THING WORK AND WHAT IS MY CYCLE.. I KNOW I AM 30 BUT I NEVER UNDERSTOOD IT....AND THIS 14 DAY FROM YOUR PERIOD IT COULDN'T POSSIBLE APPLY TO EVERYONE????? HELP ME MAKE SENSE OF THIS PLEASE...