Implantation bleeding and Pregnancy Symptoms?

My husband and I are TTC. I had a light period of 1/5 and think I ovulated on or around 1/18. Had sex on most fertile day. on 1/23 started spotting very little for 1 1/2 days. On 1/21 started getting a milky discharge from my nipples. For the past few days, I have been extremely tired, nauseated, VERY sore breasts and swollen nipples, bad headaches, bloating, and the list goes on! I am wondering if the spotting I had was from Implantation or what?!? I hope I'm pregnant, but I don't know what to think? Any advice?