25 weeks of pregnancy is about 6 months and 1 week. This means that at 25 weeks pregnant, you are at the beginning of your 7th month and getting close to the end of the second trimester.
However, it is usually not necessary to convert pregnancy weeks into months, because prenatal care is mainly based on weeks of pregnancy.
If you are unsure about how far along you are, talk to your OB-GYN or midwife. Your provider may calculate your gestational age based on the first day of your last menstrual period or measurements from an ultrasound.