yes true.. i did that accidentally a few weeks back, i created a cronjob for auto renewal but instead of renew every 2 months, it ran every 1 minute LOL - so hit the rate limits pretty quickly LOL
my thread at Too many certificates already issued - rate limit?
one way is check certificate transparency listing for letsencrypt at crt.sh | % and count how many instances of your domain there are and when they were issued
oh search your domain at https://crt.sh/ probably easier