I am 6'2" and plan on wearing leggings and skirts/dresses this spring and summer!
Leggings are my best friend right now.
I'm 5`10 leggings are very comfortable and sweat pants
I'm 6.2 and leggings saved me!! It will take some time to need real maternity clothes so you can improvise till then. :)
I would also check Nordstrom online. I am 5'11" and I tend to buy yoga pants from Costco, they sell tall, or Nike yoga pants from Macy's when on sale also in tall. They tend to work for me. But I am not quite as tall. The Nike tend to be really long for me, the Costco not much extra length. Have you look at Motherhood Maternity, some of their pants, especially their dress pants run longer than others. You could also get one of those belly bands to make your current pants last a little longer, some woman can make it work thru the whole pregnancy for them. As for shirts I like any with the gathering on the sides as they tend to be longer, even Nordstrom's Caslon tees which aren't actually maternity last thru my pregnancies for me. I also buy the undershirt from Costco (pack of 2 for $10 I think) and they are super long helping if my shirts ride up or get short. Hope this helps some :-)
Old navy clothes come in tall sizes if u go to their site, free shipping, and their clothes are all stretchy.