Could I be pregnant?

Today is day 4 of being late. I’ve taken a test each day and all have been negative. I took one this morning and it was invalid. I threw up when I ate Taco Bell. I NEVER throw up. When I was pregnant with my son I threw up every time I ate Taco Bell. But that was 2015-2016 and i havnt thrown up until now and I’ve been pregnant twice since then.

My period is never late either. But none of the pregnancy tests are positive? Should be keep testing every day or should I wait awhile?