Dear Doc

I have taken the Depo Provera Jab in Jan before I visited my boyfriend in Canada. Upon returned to SG, I did not continue the quarterly jab. I will be visiting him again sometime in first quarter of 2018. Can I take the jab again? Will I still be protected if I am only taking the jab in an ad-doc basis?

I am 50 yrs old female single.

Appreciate your advice. Thank you