What Are The Side Effects Of Yasmin?

hi i would just like to know if i should get worried that something is wrong with me or am i pregnant i took yasmin birth control for two years i stopped in june i got my period two days later since then i didn t get back my period i took a few urine pregnancy tests it showed negative by my last baby the first few urine test i took also showed negative the someone did for me it came out possitive maybe it was because it was my first time then and didn t know how to do it i don t know... whatever... do you think i should go take a pregnancy blood test or i should just wait and see what will come out of this... i am now in my 40th day and i used to be regular