vision issues?

As
I have this question in with my dr but wanted to see if anybody else has experienced this during pregnancy before. 
This morning I started to lose my vision. I wasnt just getting up or anything else it just randomly happened and it lasted for a few minutes. I'm currently 19 weeks 1 days with twins. With my first pregnancy I had a similar issue happen that my dr completely ignored. With him I'd completely lose my vision anywhere from 5 minutes to 30 or so. I'm trying not to worry too much since I didn't completely lose my vision this morning but it is also a little worrisome that it's happening and it's started this early. Thankfully it never happened while driving but it did happen at home and in the store if we were out. I don't feel this is a common thing to happen but I'm also not sure how worried I should be since my previous dr always blew it off and never talked to me about it when I'd bring it up. With my son it started late second trimester almost third trimester. 
Anyway I suppose I'm looking for anybody with experience with this and what they've been told by their dr/midwife. -also my blood pressure has never been high at all during my first pregnancy or even this one as of yet.