How Can Pregnancy Be Confirmed?

Hello, I have been trying to find out whether or not if I am in fact pregnant. But, cannot seem to get my doctor to really listen to my concerns. Ok, here s my story, since May, I have been having pregnancy related symptoms but no missed period to inform me of a tell- tale sign. So, I have been bleeding from my vagina since March. Let me start from the beginning me and my Fiancè were intimate in March 10, 2016 and normally my period comes on strong and heavy but lately it s been very short and light and from the time that I realized that I could possibly be pregnant, I ve just been getting a lot of heavy cramping, breast tenderness, and some yucky discharges since then just to name a few, I haven t been in on for an ultrasound but that s when by the time I realized that my body were going through some changes which I didn t realize until May and from May- Now I can t seem to get my doctor to take my concerns seriously and I really need to know if and in fact if I am pregnant because I am really scared and alone.