Are learning signs and counterpart signs a must to enter jhana? I have been meditating for a while now and i found my way to get into jhana, well i haven't enter jhana but it was more me not fully in knowing how but now i think i understand. But one thing i keep getting stuck on is the signs. I haven't to my knowledge experienced a nimita. Maybe cause i use visualization to enter the jhanas

From what i gathered first you have initial &amp; sustain thought. Then as time goes on you developed joy. Which brings this pleasant feeling. Then you move your attention from that to the pleasant feeling to enter rapture and the first jhana. So where do any counter or learning sign come in. Is that only for certain meditations
Important note at the beginning: I practice mainly vipassana, if samatha then I do metta meditation. Therefore I don't have a huge amount of knowledge on this subject.

What I do know is this:


What kind of sign appears to the mind depends on the chosen meditation object.
You stay with the object. Don't go with your attention to the effects of the concentration, in your post "...to the pleasant feeling". By moving to a different object you break the concentration.
I don't believe you can just pick any object. There are 40 or so possible objects given by the Buddha. Pick one of those. Also, pick the one that fits your nature. Not every object is advisable for every person.
It's good to adjust what you think of nimitta and jhana are. If you see it more as a natural thing, it can temper your expectations. Which is always a good thing. Have you ever seen figures, animals, faces or so on, in the floor when walking? If yes, then you have seen nimitta (according to my teacher). So, it's not always as fancy as we think.


Anyhow.
Here two site with more info. Maybe it can help you further.
http://rc.leighb.com/more/Nimitta.htm
http://realitysandwich.com/27172/jhanas_meditative_absorptions/