Oh, Sabby, that's TOTALLY safe. You could have had 20 tomatoes and it would have been fine.
Remember that we don't count carbs here. Tomatoes, bell peppers, beans and legumes, and dairy (LF or FF) are not only allowed in Phase 1, they are encouraged, to help counter the "flu-like" symptoms of detox. Of course, they are part of Phase 2 as well.
A cheese stick and a bunch of grape tomatoes is my "on the go" breakfast for SBD. I grab a handful of grape tomatoes, throw them in a sandwich-size ziploc, and run some cold water over them. I close the ziploc almost all the way, then tip it to pour out the water (voila! washed tomatoes!). I grab a cheesestick and I'm ready to hit the road!