Really scared. Advice?

In april I went to the doctor and had a ultrasound and he said I had a tiny cyst on a ovary but it’ll go away because we get them every month. He told me come back in two months but it most likely will be gone. I had my period in april, may, and now it’s june. It’s a week late. I took a test it was negative. I dont know what’s going on. Advice?