I naturally conceived fraternal twins. There's no twins on either side. What are my chances of having twins again?

Statistics. Chance of having fraternal natural twins is about 1 in 90. Ok so you have already won the "twin parent lottery" once. What are the odds of you having a second set of twins if your first set of twins were fraternal, then your chances of having another set of fraternal twins is multiplied by four! that's 1 in 12!
Slightly increades. The risk of twinning is about 1 per 80 births. Thus is slightly increased in older mothers, and especially those women using fertility medications. Having had a set if twins already increases the chance very slightly.