Two condoms are definitely NOT better than one. Two condoms can create more friction, which increases the chances the condom(s) will break.
If you want to be super safe, use a condom and an effective contraceptive method.
Try a different method: implant
References:
- World Health Organization Department of Reproductive Health and Research and Johns Hopkins Bloomberg School of Public Health Center for Communication Programs (2018) Family Planning: A Global Handbook for Providers. Baltimore and Geneva. Retrieved from https://apps.who.int/iris/bitstream/handle/10665/260156/9780999203705-eng.pdf?sequence=1