When pull out game ain't strong..

So lately my boyfriend has been pulling out and cumming elsewhere as when he cums inside, it causes discomfort to me, but only since falling pregnant. Could this be because of all the changes happening, or do you think there is something wrong?
__________________
Back story: sex was painful for a few weeks as I had thrush, but it has been treated and I have had no pain at all for the last couple of times, only when he cums inside.