I am just wondering when to stop swaddling and what to use once stopping the swaddle? Also I have read you should move baby into cot after 4 months is this correct.

Red Nose has the following information about swaddling/wrapping

Principles of wrapping - https://rednose.org.au/article/wrapping-babies
Modify the wrap to meet the baby’s developmental changes, e.g. arms free once ‘startle’ reflex begins to disappear which is usually around 3 months;
(Moro or ‘startle’ reflex should have disappeared completely by 4-5 months).
As soon as a baby shows signs of beginning to roll, wrapping should be discontinued.
Have a read of the article linked above for full information.

Baby should be moved to a cot when showing signs of rolling
It is essential to discontinue wrapping as soon as baby starts showing signs that they can begin to roll, usually between 4-6 months. If you wrap your baby, consider baby’s stage of development. Leave arms free once the startle reflex disappears around 3 months
If you are using a bassinette it is time to transfer your baby into a cot as soon as they first show signs of being able to roll
https://rednose.org.au/article/what-do-we-do-now-that-a-baby-has-started-to-roll-over