My eye sight is -4.50. Should I go for laser surgery?

Your
prescription is well within what can be treated with laser surgery. Both LASIK and LASEK are options for
you, assuming the rest of your eye exam is normal. Marriage is not known to change your vision (!), though
pregnancy can. In my experience,
changes with pregnancy are rare, usually small, and often revert back to
pre-pregnancy levels after delivery.
However, they can be permanent.
I have not counseled women to have all their children before undergoing
laser eye surgery. Rather, I
recommend having the surgery, and have your family, and if necessary, get an
enhancement surgery down the road if needed. It rarely is needed.

Assuming that the cornea is thick enough and that you make  adequate amount of tears you should be a good lasik candidate.

 Thank you for your question. Your refractive error is within the range of patients who would be good candidates for refractive surgery.  You will need complete eye exam by a qualified well trained and experienced Ophthalmologist.  I hope this helps.