I have very little memory left?

ever since i had my daughter my memory is shot, i can't seem to remember the little things i did last week or even a few weeks ago, i also can't do math as well as i did when i was in school and sometimes i have a hard time speaking, the speech is really bothersome considering i talk alot. the memory and talking has gotten worse since i had my son 1yr ago. is it really the "mommy brain" or is there something possibly wrong with me? my husband gets upset with me because i can't rmember to put something away and then i lose it. he has to tell me to put stuff away numerous times before i get up to do it. if i dont do it right away i forget and then it gets misplaced by me. is there something wrong with me or am i just dum?