Need advice

So currently I am 7 weeks and 1 day postpartum. I never get nose bleeds unless I’m pregnant, unless I’m extremely ill I don’t just get nauseous or almost throw up unless I’m pregnant. And I keep getting migraines which I also get during pregnancy. And today I woke up super light headed and dizzy. With my first I breastfed and couldn’t get pregnant until I stopped breastfeeding at a year. And this time I just don’t know. None of this happened with my first so I’m just wondering if anyone else has experienced this or if I should be worried and should take a test? And also how soon after giving birth can you take a test and it show up positive? I’m just so confused because I bled until 5 1/2 weeks postpartum.