Abortion pill

I honestly haven't gotten my period in three months and I've taken like ten tests. I've had irregular periods my whole life but I'm so scared. I'm 20 years old and in a healthy relationship, from time to time we don't use protection. 
I was just wondering if anyone has had this problem?
I don't want to be pregnant but what can I say, I took the risks and chanced possibilities of ending up pregnant. I'm not sure if I am because every test is negative and I've taken them within the span of the three months. 
If I am pregnant, I'm not going to have it. Abortion is my option. I'm not giving it up for adoption. I understand these are my consequences and I've done wrong, I just want to know if anyone else has been in this situation and how have you handled it