People who begin these practices usually notice changes within a few weeks. It helps to know what is common, so you neither panic nor make too much of it.
What is common
Warmth or tingling along the spine or in the belly. More energy, and sometimes trouble falling asleep at first. Vivid dreams, and more of them remembered. Desire that grows stronger for a while, as if testing you. Old feelings rising: sadness, anger, tears that seem to come from nowhere. Think of a dam slowly giving way. What was held back has to move through. Let it pass, and do not take it as yours.
What not to expect
Visions, powers or experiences on demand. They may come, or not. Wanting them is a self too, and one of the slyest. The fire is given according to the heart, not according to effort.
Slips
They will happen, in the body, in the eyes and in sleep. A slip is not the end of anything. The self that wants you to give up after a slip is the same self that slipped.
The truest sign is not in your nights at all. It is in your days: a little more patience, a little less craving, a clearer head in the afternoon, and kindness that costs you less.
This work is measured in months and years. Be patient with yourself, and steady.