There is absolutely still a chance. Think about it....there is a chance of getting pregnant while in birth control pills, iud, etc.
This is actually a very scary thing because becoming pregnant on these types of compounds can be extremely dangerous for the correct development of the fetus.
Extra precautions should be taken while using and after coming off any PEDS or anabolic steriods.
On top of that....to ensure correct development of a child a women trying to conceive or "not doing anything to prevent it" should be supplementing and taking folic acid.
Above and beyond the pregnancy thing....what does "on and off" mean? Dispite lots of opinions on female post cycle therapy....females should be doing a proper "female" version of a proper pct to regain normal testosterone levels, ensure normal ranges for liver enzymes, cholesterol, a1c etc.
I don't want to preach....but I feel as a female taking extra precautions while cycling is vital for our health.