This is a touchy subject. Medically you shouldn't be able to. But there are many, including myself, that swear within just a few days you start to feel symptoms. It verys by person greatly. I wouldn't jump on it and say they are, but there is a chance that maybe they could be.
I am approx 2-4 DPO and I have these twinges in boobs... I am sweating to death, especially at night (I live in NH) I just dont want to jump the gun and get too excited!
I have heard that you can feel pregnancy symptoms as early as the day after conception. Implantation does not take place until 6-10 days post O. It is very possible you could be experiencing pregnancy symptoms!I hope this is what you want to hear :)
Jackie TTC#3
Cassie