Apply for H4 on spouse's visa while my H1B extension is pending

I work for a big firm A and have an h1b extension pending. My I-94 expires on Aug 30, 2020.

Receipt date of the h1b extension is 26th may 2020 and since this is normal processing, I’m assuming the approval will take a long time, way beyond my I-94 expires. Additionally, I’m expecting an RFE as my home address is 100 miles away from work address, I have a long commute.

My husband has a valid H1b with a different firm and we are considering applying for my H-4 visa before the I-94 expires.

If my h1b application is approved, I’ll withdraw the h4 petition. If h1b is denied, I can fall back on the H4 visa.

Would this be a sound decision?

Edit: What should I give as my start date for H4?

What if H4 is approved before your withdrawal?

Do you know that there is no guarantee that USCIS will approve or withdraw within a time frame that you expect?

If your H4 is approved, you will not be able to work at all from the day it is approved. Then, chances are very high that H1B will be denied too.

Not sure who advised you to do this but i do not suggest it.

Thanks for the response. So, I looked at the processing times on the Texas service center website, it said 4-6 months for h1b and 6-8 months for H4. But these timelines don’t mean anything?

Also, say I don’t apply for H-4 and wait for the H1B result beyond my I-94 expiry. And in the worst case situation, the H1B petition gets denied. Can I go to Canada and get a new H-4 visa? Or do I have to go to India? I am asking cos I am pregnant and may not be able to travel to India.

You can get H4 visa stamp in Canada.