My husband and I have been trying to concieve for almost 4 years now. We just started infertility treatment (IUI). We're on day 3 of injections and we've gotten into an arguement every night.

We generally never argue about much, so I'm worried about what the stresses of fertility treatment is doing to our marriage.
One day one, we argued because we were both just really nervous and stressed out about doing the injections correctly.
On day 2 of injections, we argued about him asking me to find someone else to give me my injections so that he can hang out with an out of town friend. He realizes now that he should be here and decided to meet with his friend after he gives me my injection.
And today, we argued because he had 3 beers. Although the doctor said that he can drink in "moderation", it bother's me that he won't sacrafice drinking just for ONE WEEK, if not drinking could possibly increase our chances of conceiving. Don't get me wrong, it's not like he drinks daily. He's more of a weekend drinker. But I just expected that he'd not drink while we were going though treatment.
Is it normal or common for fertility treatment to cause strain in a couples marriage? Or is there more that I should be conerned about? Remember, we're normally a very happy and playful couple.
Please help!
Thank you