Hey wonder..
each aas has a different half life and duration.. so stacks are like a science mixing chemicals that will enhance each other and cause the least amount of sides..
so there is no static or set time length of a cycle..
the average for most cycles are about 12 weeks.. but the more androgenic, the lower the length of cycle and the higher anabolic, can be stretched out to 16 weeks (ie:var) so it really depends on the drug...

loss of period may or may not occur with the use of aas.. every woman's balance of hormones are different thus every affect will be different.. unfortunetly no static either.. I can say that the harsher androgen and the more suppression of your estrogen, the more likely the loss of periods.. BUT also low bodyfat and hard exercise will cause of a loss or diminished periods..

does that help to answer your questions a bit??