Probably not. I do not know of any specific California law on the subject, but other states have found that pregnancy is not related to the performance of teaching duties, and thus does not provide a basis upon which to fire a teacher for "moral turpitude". Past practices with pregnant single teachers may be relevant. See, e.g., New Mexico State Bd. of Educ. v. Stoudt, 91 N.M. 183, 186-87, 571 P.2d 1186, 1189-90 (1977) (concluding that the State Board of Education's decision to terminate the employment of a pregnant, unmarried teacher for immoral conduct "was arbitrary, unreasonable and not supported by substantial evidence" based in part on the fact that the local school board had retained five unwed mothers and had taken no action against them).

If you are in a unionized position, I suggest you inquire about your rights with your union.