Is the only way u can get pregnant is fertile days?

Naturally, yes: In vitro fertilization is the only way to get pregnant without ovulating. Otherwise ovulation typically occurs 2 weeks after the first day of your period (assuming a regular 28-day cycle). Sperm survive up to 6 days in the female body, so sex even 5 - 6 days prior to ovulation can lead to conception, thus the concept of your fertile days. Careful though; they can be unpredictable at times.