I had metastatic papillary thyroid cancer and never had rai after total thyrodectomy. I wanna take it soon. Was it bad I didn't do the rai right away?

Lucky. You may simply be a lucky person--not everyone needs to have rai, particularly those with small tumors. Discuss it with your surgeon and/or endocrinologist. If you do indeed need it, don't worry--there is still time.
It is controversial. Absolute benefits of rai are debate able to begin with thus timing is even moreso. Depending on how lng of. A period of time has lapsed you will want to speak with your endocrinologist to decide if new imaging as a baseline is needed prior to taking rai.