Is it a possibility that I'm pregnant? Need advice :)

I had a period in the beginning of October and I have sex twice on my fertile days. 28 days later counting from the beginning of that period I had another one that was heavy at first then slowed down and was shorter. I found it odd! I'm now 3 days late for my period,on day 32 of my cycle! I've been peeing way more frequently starting today,more tired,a little nausea and started having small cramps a few days ago but no period. I feel wet down there like I'm gonna start but nothing yet. I was using the withdrawal method(not trying to get pregnant or prevent it) so has this happened to anyone??