Ignore this if you wish as I'm going to ramble on a bit. Exactly what Husky said. I'll throw my two cents in. I have very fair skin and as a doctor once said to me many years ago, "John , you were born in the wrong hemisphere and its only a matter of when not if".
That filled me with a great deal of confidence, but this set me on a path.
This is what I recommend you do.
Find yourself an aggressive doctor who freaks out at every blotch, red mark or mole they come across. I've shopped around a bit and have come across GP's who are more conservative than they should be. Whether this is lack of expertise in this area or not wanting to overreact to every blemish I'm not sure. I had a mate, correction, I have a mate who like Husky , was worried about a mole on his shoulder, GP disregarded this for several years, mate finally gets second opinion, mole has gone troppo, big cut, big scar, big scare. His shoulder is now one huge scar and he's lost strength in it as well. So get a good GP or Skin Doc who has a plan.
Go to a mole/skin clinic and get them to scan your body with a camera, good ones will scan and photo any spots they are concerned about. I walk in to my doc and he has my spots and blemishes up on the screen to check. He has referred to what he needs to do as gardening, sunspots and so forth are like weeds and need to be constantly clipped and dug out. He is aggressive and considering up 95 % of skin cancer is curable with early detection I'll let him slice and dice his little heart out.
I visit the clinic every 6 months, I'm a little paranoid but considering 6 months isn't a long time in an aggressive skin cancers life I think I'm justified. Check yourself and ask the missus to have a look at the bits you cant see. If they're anything like mine then they'll hound the fuk out of you until you do something about whatever they find.
Sorry to ramble but early detection is the key in most cases, not all , but if your not getting checked then you're doing yourself a dis-service.
Harko