If there is no proceedings going on between you two and this is just an in formal separation, you both have equal custody rights to take care and be with the child. You cannot be barred by anyone to meet your child, however, in many cases when a father visits the child at the in-laws' house they file false cases.
You should go for a parenting plan and get it approved from the court. You can add the number of days, place of meeting and other things in the plan and once it is approved, the same shall be followed.
You may even get the child custody in a custody suit of the odds are in your favor which may include factors like - age of the child, his emotional attachment with both of you, financial position of you both, etc. So according to your real position right now you can choose either of the steps, however, do not bunk taking legal guidance from a good lawyer on the basis of this reply. He shall guide you in the best possible way.