According to the search results, the chances of getting pregnant without protection depend on various factors, such as age, frequency of intercourse, and use of birth control. Here are some key findings:

• Over the course of one year, 85 out of 100 women who do not use any kind of birth control, including condoms, will become pregnant.
• At least 85% of women who continue to have sex without birth control, even just once in a while, will be pregnant within one year.
• The CDC estimates that women under 30 who have regular unprotected sexual intercourse are more than 75% likely to become pregnant within a year.
• The estimated average chance of pregnancy per menstrual cycle for couples trying to conceive is between 15% and 30% in high-income countries.

It is important to note that these are general estimates and that individual chances of getting pregnant without protection may vary. Additionally, there are many effective methods of birth control available that can greatly reduce the risk of unintended pregnancy.