It sounds like you feel monitored which can be very uncomfortable. Perhaps it is time for a talk about trust and insecurity. Women who constantly need to know where their partner is often have issues with trust and self-esteem such that if the partner is not readily available, they automatically think they are spending time with someone else. Talk with your girlfriend, discover what drives her behavior, establish boundaries and see if the pattern changes. If not, evaluate the relationship to decide if she is the right partner.