I have a question about blood types, for example if both of my parents are o+ or o- is it possible for me to have something other then either o- or o+ bloodtype?

No. With the rare expectation of one of your parents having what is called a Bombay phenotype, that may look like O but could be A or B that is hidden by the Bombay phenotype, though the person can transmit the DNA for Blood Group A or B. Visit this site for this rare circumstance: https://www.ncbi.nlm.nih.gov/books/NBK2268/

Technically no, but in real life, yes. That is because across the globe, in all communities since the beginning of time, families have adults and children in which not all of the children are direct genetic offspring of the adults. That's normal in human life. All doctors know it and don't make a big deal of it unless there are special medical circumstances that need exact family tree mapping.