Is there any harmful effect on taking of birth control pill for a long time like 4/5 years before 1st child? if yes then what type & what should i do?

Need more info: I assume that you are getting regular GYN exams when you have to renew your birth control pills. If so when you stop the BC pills your periods should return. After you have the second period there should be no harmful effects should you get pregnant.

Suppress ovulation: on some cases the birth control pills suppress the ovulation for a long time after the pills have been stopped,it is not common, but it can happen.usually the best way is to give the body a break, and try diffrent way to prevent pregnancy.like using intra uterine devices, condom, spremecide, provera (medroxyprogesterone) shut.etc.... good luck

Pills: Shouldn't affect fertility. Have you considered some alternative means of contraception such as an IUD

Taking oral: contraceptive for five years should be fine. The woman can see physician or gynecologist to discuss which pill is best for her.