I am in trouble againe !!

I was preparing my absence list and listed all the stamps from the passport and realised that there is one arrival stamp missing.
I visited the home country in between 07th October 2002 to 31st October 2002 for which I have two stamps,
1. Arrival at the home country
2. Departure from the home country
but there is no stamp for arrival at london Heathrow on the 31st of October..
I suspect it is either buried underneath many europian business visa stamps (as they take the complete page) or has not been stamped.
Is this a problem ?
Any clarification on this would help. THanks.