My girlfriend (32F) is usually quite affectionate towards me (40F) however it's been dwindling and lately its almost just coldness for the last few days. She told me it's work that's stressing her out.

When I asked her to tell me more she clamps up. She then told me when she has problems she prefers to deal with it on her own. I try not to take it personally but its getting harder and harder not to think that maybe it's not just a work problem.

Our relationship is still fairly new (6 months) and in this 6 months she would usually tell me whatever is bothering her. However nowadays it seems like she is selective on what to tell me is bothering her. I've always been very patient to listen to her rant.

We never had like a fight fight before and we would agree to disagree when it comes down to it. Just 2 weeks ago, me and her were making love like crazy and having a great time hanging out. Overall I feel our rs is good. However in the last week or so shes been planning more nights out with her friends and coming home late.

How long more should I wait before really asking her again what's going on? Currently this cold spell is on its 4th day. I'm pretty sure I didn't do anything wrong.

Tldr: relationship gone cold, girlfriend says she is just bothered and stressed with work matters. I'm beginning to suspect it's not. When should I ask her again what is really wrong?