@ohitsnicola Obviously I can't advise you about your doses, but when I had highs like that in late pregnancy I corrected them (and tested lots after).
Your ratio may need upping for that meal, but don't make any decisions from one result. I used to wait till I had 3 highs after a meal to change the ratio (but I still corrected in the meantime) If you know a particular meal is giving you highs, you can have the same meal the next day and see if the same happens.
For 'dodgy' meals where I thought I might go high, I tested at 1 and 1/2 hours so I could catch the high early.
After about 30 weeks or so (don't remember exactly) my insulin needs increased a lot eg my evening meal ratio went from 1 to 10g pre-pregnancy to 1 to 4g.
So do correct if you're confident doing so. Also, you may find that certain carbs are more difficult to eat in the last few weeks eg I found I could no longer have juice at breakfast. It may be your big glass of milk was the issue.