Stress may have an impact
Stress is known to have the ability to disrupt a normal menstrual cycle. Hormones released during stress otherwise harm the overall health, but when it comes to a period, they have a more evolutionary, primal role.
Essentially, your body's hormonal balance during stress will disrupt and result in late ovulation. In some women, ovulation may not even occur during stressful times.
Scientists explain this with the body's strategy to avoid pregnancy in an uncertain environment. Essentially, stress signals that your body is under distress and not in a safe environment. In some cases, a mechanism to prevent pregnancy activate in form of period delay.
How this relates to traveling on your period? Not all trips and vacations are stress-free. You might have a great time, but if you drink too much and sleep too little, your body is actually suffering stress.
Stress can suppress the pituitary gland functions, affecting the production of estrogen, which in return disrupts the ovulation. You can trigger this body response even if you mentally feel good, excited and entertained if you're partying too much and sleeping too little.