Could implantation bleeding occur after 10 days of spotting?

Yes: Hard to say without more information. It would also be hard to differentiate spotting from implantation bleeding. Take a pregnancy test if you're wondering about implantation.

Why do you ask? : This is a metaphysical question - how can you tell if you had impantation spotting if you are spotting already? The answer is obviously you cannot and you could be pregnant, albeit not likely. Check a urine pregnancy test within 1-7 days of a missed period to be sure and see your gynecologist to be even more reassured. Take Folic Acid 1-5 mg daily and best of luck!