Here is mine for comparison. Hope yours is the proof - the regular business strike had no mintmark (as non_cents mentioned.)
Thank you all for your replies. Unfortunately after researching, it does appear to be a business strike 1970. I also have a 1968 dime with no mint mark, I suppose there were business strikes that year with no MM also. Bummer, the excitement was fun while it lasted! I am really not a dime collector, just happened to find these. I do have tons of penny error coins I would love to have graded though
Unfortunately, NGC decided that this coin was NOT a cameo. I must have submitted my coins on "monkey gets to grade coins day."