Does anyone know if there is anywhere you can visit over the weekend for a breast exam, or will I have to wait for a GP appt on monday? Is this worthy of an "emergency" same day gp appt if I ring on monday? There are no available appointments for about 2 weeks.

I feel very worried as I have had a lump in my breast for many months, I think it has been a year in october time. I had it checked out in november but my gp said she thought it was just lumpy breast tissue. Fast forward to now, I've been getting stabbing pain in my nipple (same side as lump) mostly when i lift my arms up and the same nipple also keeps turning white when I put my arms up. I also today have noticed a very subtle dimple/dent underneath my nipple and it looks like my nipple has slightly changed direction (facing slightly more downwards and outwards towards the dimple). My other nipple points straight, but I know we cant be perfectly symmetrical! I also noticed 2 weeks ago in the mirror that I appear to have a small lump on my chest, below my collarbone but not directly underneath, more like 2nd rib area, but I wasnt sure if it was just my rib or cartliage sticking out slightly more than the other side suddenly - I have had a cough and chest tightness for over a month, and thought maybe the coughing had caused inflammation or something! The tightness is also worst when lying straight on my back. 

I'm only young so I know this is likely to be benign, but the dimple or dent has really worried me and now i'm feeling frustrated that I might have to wait to get it checked out, but I'm unsure if there are any services I can access over the weekend. If anyone knows, would be very appreciated!