A little advice please?

So my DH and I have been doing the baby dance on the regular as we are ttc baby number one. Had a negative test at 10dpo which was pretty devastating as I was really sure it was my month. But we have had BD twice since then and AF is due in 3 days. Is there any chance I could get pregnant (aware I can't test for a while) just would like to know how possible it is. 
On another note, don't know whether it's AF or not but my boobs have been GREAT the last day or so, they honestly look fake!!! They're just staying there on their own!! Slightly sore but hey who cares!! A welcome change but I doubt they will stay :( hahaa 
Baby dust to all you ladies, I hope someone will give me some advice.