what to do emoitionally

i had a 1 night stand a lil while ago, and was with a different guy 2 days later, im having possible symptoms n scared out of my mind! im a single mom. i hadnt been on my ap in a lo g time tracking n my periods been irregular since my last child, i never planned on being sexually active, but am on the pill... im due to start sunday by my pill, but not til thursday by this app.... should i test? when? what do i do if i am 😢 i am scared, this is new experience 4 me... ive never been with anyone out of a serious relationship, recently went through a divorce of a 15 year relationship, married for 12 with six kids