help!!

Hi, I have been worried about this. The thing is that I have almost a year with my bithcontol I take it very seriously I have never missed a pill for more that 30 min, I'm really concerned because last month my period had to come and I just saw some spotting, I was under a lot of stress because it was finals week. Now I'm waiting for my next period that it was suposed to start on Friday and I haven't seen anything. What are my chances on being pregnant? I have a partner but I have not taken any atibiotics and y was very constant on my pill. Please help me 🙏🏻