H4 extension, when H1 to H4 conversion is still pending with USCIS

[SreeLathaG]

Hi,
Could you please help us with the below questions, regarding the filing of i539. I have applied for a H1 to H4 conversion in Feb 2018. I have received the receipt notice and the application is still process with USCIS.

Here is a brief background about my visa status:

I applied for H1B extension under the maternity clause in August 2015. The extension was denied in Sep 2016. I was asked to leave the country at once and return on a H4, by my employer. I applied for a MTR before leaving.

I returned in Jan 2017 with a H4. One week after I returned the MTR was approved and the H1B was approved till July 2018. My online i 94 has H4 visa with an expiration date of 10/08/2018.  The latest i-797 after the H1 extension was approved will expire on 07/10/2018.

I applied for a status change from H1b to H4 in Feb 2018.

Below are the questions I have.
a) My online I94 shows the H4 visa, but the one on I797 is for H1B. So what would be my status as of now, H1B or H4?

b) My husband’s H1B will be submitted for extension in August 2018, can I file for the extension, with him now? Can I have 2 applications submitted to USCIS at the same time?

If I can apply for the extension, what should I fill in for the below questions in i539 form.
1. 12.a and 12.b questions. The questions are regarding my current status, should we fill 12.a as H1B or H4. My H1 will expire on 07/10/2018.  Should we fill in the 12.b expiration date as 07/10/2018. 
2. 11.a, which is about the latest i 94 number.
3. Should we mention that her conversion from H1 to H4 is in process? If so, where and what details should we provide?

Thank you for the help.

SreeLatha