Early pregnancy symptoms?

Hubs and I BD'd on the 18th, 26th & 27th...I'm only 5dpo.

I had mild cramping a couple of days ago and since yesterday, my boobs/nipples have hurt SOOOO bad! Extremely sore to the touch, can't stand to wear a bra or sleep on my stomach. They've been swollen since yesterday as well. I've never had my boobs hurt like this, not even on or close to my period...which isn't due for another 13 days.

Is it too early to be experiencing symptoms?