The EDD uses a base period of four consecutive quarters, and bases your benefit amount on the quarter in which you made the MOST money. You did not mention how long you were on maternity leave, but in your situation, depending on when you filed your claim, the base period may have run through the second or (possibly) the third quarter of 2012. So basically unless you were out of work for nine months or more, it is unlikely that your rate was affected by your maternity leave.
The amount that you made "after taxes" is not relevant -- the question is how much you made in your best quarter BEFORE taxes. Then you can take a look at the EDD Benefits Guide (link below) and see whether it matches up. If not, then contact the EDD to discuss.
Best of luck to you.
Disclaimer: This reply does not constitute legal advice or the establishment of an attorney-client relationship, and constitutes only general guidance based on the limited information provided, and may not take into account additional relevant facts and circumstances pertaining to your specific situation.