Chances of being pregnant?

Hi there, im unsure of whether or not i am potentially pregnant. The anticipation is killing me and i was hoping for a little guidance on what exactly to expect before i take an at home pregnancy test next week. I am currently two days late on my period. All last week my breasts were sore and slightly swollen, i have never experiences breast pain as a period symtom so thats when i began to question it. I have had very slight cramps and have progressively become more tired. this morning was the first morning i began to feel nauseous although it subsided throughout the day. I have been EXTREMELY moody and there is a sort of thick mikly colored discharge coming from my vagina, the sort you would see during ovulation. I am teetering on whether or not this is just a late period or the first initial stage of conception, as in the first week or two. I am visiting a doctor within a week if my period still hasnt come, i was just looking for a second opinion on here. Can anyone help.me out