Is ovum + ovum fertilization possible for human?
Using a somatic cell in an a ovum is what is typically done in the process of cloning.  It was the same process used to create Dolly the Sheep. What you're asking about is something very different:

Consider that somatic cells are properly diploid.  Whereas an ovum itself just contains a haploid number of chromosomes. In typical sexual reproduction the sperm fertilizes the ovum which would than bring the chromosome number to to correct tally.  So combining the genetic material in two ovum should bring the chromosome count to the correct tally as well, but scientists would need to somehow motivate the  activities that happen when typical  sexual reproduction occurs. It's likely very challenging to do that if not highly improbable. Should it work, this process could only produce female children.