Hi, welcome to HCM.
will get resolved with antibiotics . No need to worry about that.
Second thing increase in pituitary fossa. It is common after pregnancy
. It is known as physiological hypertrophy. It is also increased in puberty
I think if you dont have symptoms like headache, blurring of vision then no need of MRI
on emergency basis. .
Wait for 6 month then if signs persists, MRI xan be considered.
Hope I have answered your query.