Hi sheoran ,
According to your data, you will get pre-aor in first week or mid of march and since your ielts will expire, so would your ee profile will. Moreover, your ielts hard copy will reach you till 20th march. What i would suggest is, that you would have to recreate your ee profile once it gets expired and update the details. Further, in case you get your pre-aor, prior your express entry profile expires, you would have to email your new ee number to nova scotia by communicating with them on email, which i previously mentioned you. Also, i think after pre-aor, it takes another three weeks to finally get nominated from any province.