Some SMS messages sent to my iPhone go only to iPad - why?
When someone sends an SMS to my phone number (this may be someone without an iPhone, so I suppose not part of the iMessage system), I sometimes see it in the 'messages' on my iPhone but sometimes it doesn't appear there: on the other hand, all messages sent to my phone number appear on my iPad (on the same wifi network as my iPhone, if that matters). If I look at the messages on my iPhone right now, I see messages sent a few days ago, but not one sent yesterday, which is clearly visible in 'messages' on my iPad! I don't think I have changed any parameters lately.
It is obviously vital that all messages (iMessage or straightforward SMS) sent to my phone number should go to the iPhone with that number, specially if I don't have access to my other iOS devices - how can I ensure this?
I have looked at other discussions here but I can't find a straightforward explanation of this. Can anyone help?
iPhone 5, iOS 7.0.3, 16Gb