I Feel sex deprived when I a pregnant

Ro

So I have 4 children (3 daughters and 1 son) from a previous relationship, long story short I remarried we have been together almost 7 years this is his 2 relationship he has (1 son)..... I had cut and burned my tubes 10 years ago after having my son this was not a deal breaker when we got together I explained I couldn't have more children when he started talking about having more well little did I know he was going to make it all happen he looked up a fertility doctor took me paid to get a tubal reversal and now we have a beautiful 17 month old baby boy and we are expecting i am due next month March 25th 2020 just found out on his birthday January 11th we are having a another boy we both would like to have a girl together so he is now talking about being pregnant a 3rd time from him and paying for a gender selection pregnancy to be done with this man is incredible he is very hard working and loves our son but I notice that last time I was pregnant and this time as well he turn the fire I love in him completely off and ge goes months with out touching me or asking for sex I'm always on fire I never say no I'm burning up here how to tell him what is the problem this mama needs him to be like his usual self hot as always dont get me wrong he asked for oral but that's it and when he is done life goes on but what about me I need some action is anyone in this same or similar boat as me please comment and give me advice on how or what to say to him to bring this all up