The official Lariam site
here makes interesting reading and gives a really frightening view on the cycle of the killer disease, Malaria. The notes say that you should complete the dose after the visit, unless you exhibit certain severe contra-indications. You might think that the mighty drug company "would say that, wouldn't they?" to get you to buy the drug, but there is no vested interest in telling you to continue with the treatment longer than necessary as you already have the drug, and it is not as if you have to go out buy lots more. They are probably telling you the most effective way of using their medication.
Not all people react to mosquito bites (I don't) so it is hard to say whether or not you have been bitten. On balance I should continue the dose indicated. A bit of light headedness or nausea is preferable to suffering Malaria or even being dead.