If you're not burning then there's little risk of melanoma
Tanning indicates that your skin reacts, so there's a risk of the usually-non-nasty stuff like squamous cell carcinoma. But the tan will protect against that.
On the whole, I'd not worry* but I'd keep watching for lumps etc
*unless you're deliberately sunbathing or visiting hot climes, then I would use suncream if I were you. Or even better, cover up.