Ahmadiyya is not a branch of Islam
Qadianis (self-proclaimed Ahmadiyya) were unanimously declared \"non-Muslims\" by all competent bodies all over the world (there is absolutely no disagreement amongst Muslims scholars). For Example :
- Islamic Fiqh Council of the World Muslim League (KSA) (Please kindly read the resolution for further details http://en.themwl.org/content/third-resolution-qadiani-sect-and-associating-it)
- Islamic Research Academy at Al-Azhar University (Egypt)
- Islamic Community of Bosniaks (USA)
- Islamic Fiqh Council (South Africa)
- Permanent Board for Inquiry & Fatwa (KSA)
- Shariah Council (England)
- Organization of Islamic Conference (KSA)
- Supreme Islamic Council (Gambia)

By the way, these are some articles which explain why Muhammad (peace be upon him) is the last prophet and messenger of Allah the Almighty
http://en.islamtoday.net/node/1746
http://en.islamtoday.net/artshow-293-4056.htm
http://islamqa.info/en/113393

Please kindly check It out by yourself...These are some blasphemous beliefs (against the Prophets peace be upon them and even against Almighty God) from the authentic writings  of the imposter Mirza Ghular Ahmad.
http://www.janathimessage.co.uk/Literature/Beliefs_of_Ahle_Sunnah/BeliefsofQadianies.html