what’s wrong w me 😶

I’ve been having sex without a condom (using the withdrawal method) & my period still came every month. I always have sex outside of when my period tracker says I’m in my fertile window and so far I have not been let down. Last week Monday I had protected sex & I was supposed to start my period 5 days ago. I’ve been having little cramps but no period 🤦🏽‍♀️ I’ve always been so careful but the end of the month is approaching. I’m trying not to stress but this shit is stressful. I took a test and it came back negative... & I’m trying not to stress about it. Someone please tell me something 🤦🏽‍♀️