6dpo Symptoms

Taija.
Hi ladies, 
​I would like some help!!
​I'm now 6dpo I have Extremley sore boobs to touch they feel soo heavy this started yesterday afternoon really and this morning I woke up at 4:45am with extreme heart burn which I rarely get !! Feel a bit run down today ?
​What do we think? Is it even possible to have symptoms so early? Is it just in my head because I feel a bit run down anyway??
​Be honest
​Thanks x