3 days late

Im 16 and i have had protected sex 3 times this month. After everytime i check the condom either with water or by blowing in it. Last months my period lasted for 6 days but i spotted for two days after the 6th day. Now im three days late for my period. Can that be the reason why? Also i am having period symptoms but I'm nervous because i have only been 2 days late not 3. Please help