ssalamu aleykum,

Contraception is never a sin in Islam. If you feel that you don’t want to have children, it is your right to prevent pregnancy.

Please refer to the book Marriage and Morals in Islam:

According to the Shi 'ah fiqh, family planning as a private measure to space or regulate the family size for health or economic reasons is permissible. Neither is there any Qur'anic verse or hadith against birth control, nor is it wajib to have children in marriage. So basically, birth control would come under the category of ja'iz, lawful acts. 

https://www.al-islam.org/marriage-and-morals-islam-sayyid-muhammad-rizvi...

From Marriage to Parenthood: The Heavenly Path 

https://www.al-islam.org/from-marriage-to-parenthood-heavenly-path-abbas...

Here below you can read more about contraception in general on an Islamic point of view:

https://www.al-islam.org/islamic-edicts-on-family-planning/birth-control

https://www.al-islam.org/islamic-marriage-handbook-syed-athar-husayn-sh-...

And because you just got married, I strongly suggest reading the above books from the beginning to the end to help you out in your married life inshaAllah.