LH surge with twins

When I conceived my F twins, it was before opk's existed. Not to mention they were uh-oh babies :). I'm wondering if you all were testing prior to having twins and how long your LH surge was the month you conceived? I had a 5 day surge this month and I'm pretty sure I conceived but now I'm worried about possible twins😳. I read online a long surge can indicate 2 eggs being released. Now I'm panicking haha! I can't say if or if not I have long surges because I always stop with the 1st +opk, however this month i continued to test for giggles.