We had unprotected sex with pull out method around ovulation time this month. Today suddenly i started bleeding , 5 days before my expected period. I am usually 2-3 days late, very very rarely early. Till now bleeding is not strong (started only around 2hrs back), mucus heavy, mild cramps, back ache, leg aches and a little gassy. Coukd it be implantation or period is early? Lmp was on 21stoct and avg cycle length is around 32 to 34 days.