What Causes Vaginal Pain And Mood Swings While UPT Is Negative?

I missed three pills (microgynon 30) at the start of a new pack and took no extra precautions. I stopped without taking the last three, had a light period, took a pregnancy test, which I don't think worked as there was only one horizontal line and nothing in the indicator window. I continued onto a new pack, but have been experiencing vaginal pains and mood swings. Should I take another pregnancy test or is this just because I mucked up a pack?