I installed bluestacks and whatsapp in it on my pc, sent the verification code to my twilio account, however I'm not receiving any confirmation code sms. If I send a normal sms from my phone to the twilio number it is received and displayed normally in the logs, but the whatsapp verification message isn't.
Twilio developer evangelist here.
There are many reasons you may not be receiving SMS messages to your Twilio number. In this case it is likely that WhatsApp are trying to send the message using a short code or alphanumeric sender ID. It's also possible that WhatsApp refuses to send verification codes to VOIP numbers, like Twilio numbers. In general it is not a good practice to use Twilio numbers to receive verification codes.
There is more discussion on this sort of thing on this question.