### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
hi.. i ve been taking pills since july 2012, i was using azul, but last month, february , i changed my pill to althea, and i took the first tablet even if i was done with my menstruation . it was stated on the instructions that it s ok to start the pill at any day as long as you follow the days indicated on the pill pack. but on the first week that i was taking the pill i was also taking antibiotics/antibacterial named amoxicillin . and i had made out with my boyfriend on the 5th day that i was taking pills. i finished my 21st tablet last march 2 and it s already march 6 today and i still don t have my period. the last day of my period was jan. 30.. i did some research and it says that antibiotics don t interfere with the pill except the one named rifampin. so i m confused, am i pregnant? pls help me. -AAAAAAA. stressed out-

### output:

Hello, Thanks for posting, Well I do not think you are pregnant if you have been taking the pills as indicated even though it will be wise to conduct a pregnancy test in about a weeks time just to be sure that pregnancy is not the cause of your amenorrhea. Pills are hormone based and can alter the concentrations of your natural hormones there by leading to menstrual irregularities. Since you changed abruptly your initial birth control and introduced a new one, it is possible that it is the change that lead to this. Menstrual irregularities e.g., spotting, breakthrough bleeding or amenorrhea can occur during its use. Most of these side effects are mild and usually disappear after a few months of contraceptive use. So I suggest you worry less than stress on its own can lead to menstrual irregularity. Hope this helps