Husbands ravenous sex drive a problem?

Ash • Married 8.2.2014. 1st Boy 11.24.16. 2nd Boy 8.27.18
Since being pregnant, my husbands sex drive has literally quadrupled. I'm 9 weeks and still very sick all the time so I just don't have the energy and my body just hurts as it is. He asks me a couple times a day to have sex. I mostly decline. He has expressed that for some reason even just seeing me, he gets a raging boner. Lol Well last night he told me more detail. Apparently, on top of all that, he is masterbating twice a day. He's actually concerned because this is not normal for him at all. Lol I think it's funny but also inconvenient because I am no help. Anyone else experience this??