It is common for women to have different rates of growth during pregnancy, so it can be challenging to determine the exact number of weeks or months based solely on belly size. However, feeling your baby's movements can provide some insight into your pregnancy duration. At around 18-25 weeks, you may start feeling fluttering kicks, which gradually become stronger as your baby grows. Considering this information, it is likely that you are around 4-5 months pregnant. To get a more accurate estimation, it is recommended to consult with your healthcare provider who can perform an ultrasound or physical examination to determine the gestational age of your baby.