Inclusion Criteria:  currently <16 weeks pregnant with a single infant at least 18 years old normal weight, overweight, or obese body mass index prior to pregnancy can read English at a 6th grade level planning to continue pregnancy to term owns smartphone and keeps it within arms reach during the day willing to allow medical chart access for specific information during the current pregnancy no absolute contraindications to exercise, i.e., a doctor has not told you not to exercise during pregnancy  Exclusion Criteria:  pre-pregnancy BMI <18.5 kg/m2 age <18 years gestational age >16 weeks multiple gestation not planning to continue pregnancy to term does not own a smartphone or keep smartphone within arms-reach during the day pre-pregnancy type I or II diabetes absolute contraindication to PA in pregnancy not receiving prenatal care or not willing to allow access to medical chart inability to read English at a 6th grade level.