My girlfriend is worried she might be pregnant. We had sex 3 months ago on her period. Since then shes had two regular periods. This month, shes over a week late. Shes had no morning sickness, no sex-drive changes, no cravings or appetite changes, no fatigue, and only mild increase in weight and belly size (due to moving in with her grandparents and eating better.) How likely is it she is actually pregnant?