Light headed

Christine • Rainbow baby boy born January 2017 🌈 after a missed miscarriage Dec`14, molar pregnancy Apr`15 and blighted ovum Feb'16
Hi guys. Today is day 31 of my cycle, which is usually 28-30 days long. I haven't taken a hpt yet. Today i woke up and without even getting out of bed i felt very light headed. My blood pressure is usually on the low end of 'normal'.  This has never happened to me. Have any of you ever felt like this?