No only should you be qualified for unemployment, since you have been terminated not "for cause" (i.e. not for doing something like insubordination, unauthorized absences, violating company policy, etc.), but you may have a claim for illegal sex-based discrimination: it is illegal to discriminate against a woman, such as by refusing to employ her, due to pregnancy or having had a child (since only women get pregnant, taking action against someone because of pregnancy or having had a child is seen as anti-woman discrimination). It would be one thing if they had eliminated your position entirely, finding, for example, that they did not need it; but to let you go and replace you under these circumstances implies the real reason is your pregnancy and need to pump for your child. You should contact the EEOC about filing a discrimination claim; you may be entitled to compensation.