Background: Fertility and family planning are key areas of focus for adolescent and young adult (AYA) cancer survivors. Pregnancy intention is associated with preconception health behaviors in general populations of women, but few studies explored the role of intention among female AYA survivors. Aims: This dissertation aimed to evaluate: 1) associations between pregnancy intentions and preconception health behavior (specifically: physical activity (PA), cigarette smoking, and alcohol consumption), 2) potential moderation by perceptions of post-cancer treatment infertility risk on preconception health behavior, and 3) factors associated with infertility risk perception and risk estimation.Methods: Data for this dissertation came from participants of the Reproductive Window in Young Adult Cancer Survivors (Window) study, a longitudinal study to estimate the trajectory of ovarian function among AYA survivors. Participants were followed for 1.5 years encompassing 4 data collection time points from baseline and every 6 months. Study #1 utilized baseline data to evaluate associations between pregnancy intentions and preconception behavior with regression analysis. Study #2 utilized data from all time points to estimate the association between changing pregnancy intentions and preconception behavior with longitudinal mixed effects models. Both Study #1 & #2 evaluated potential effect modification by infertility risk perception. Study #3 utilized baseline surveys, medical chart abstracted treatment information, and biomarkers collected to measure ovarian reserve. Multivariable logistic regressions evaluated associations with perceived infertility risk and with risk estimation between perceived and objective infertility risk. Results: Study #1 and #2 found urgent pregnancy intention was associated with higher preconception PA. In Study #1 survivors with higher pregnancy intention and perception of infertility risk reported higher PA compared to survivors who did not perceive infertility risk. In Study #3 experiencing either higher gonadotoxic cancer treatment or amenorrhea was associated with higher odds of infertility risk perception. Poor agreement (ĸ =0.19) was found between perceived and objective infertility risks. Conclusions: This dissertation provided insight into the role of pregnancy intention on preconception health behavior and identified factors that may inform perceived infertility risk. Knowledge gained from this dissertation may guide behavioral interventions targeting female AYA survivors and inform infertility risk education needed within survivorship care.