Devastated 😭

Since the new year my partner has been acting "strange" been a bit distant, only engaging in sex every so often, been ignoring my calls, texts and even me for days on end. He's 30 in a few days and he still stays at home with his mum. He blamed this lack of affection and withdrawal of commitment on depression. We were so close before this and trying for a baby and looking for a house together. Anyways, I lent him an old phone of mine before Christmas and after ignoring me since last Saturday even though my 4 year old child was in hospital with blood poisoning I ended the relationship. I got my phone back today and out of curiosity checked location services. I feel bad for doing it but I found that he had been staying at a different house most nights since the new year. The times would work out that he would leave me at a certain time and end up going to this address and spending the night there. Even Valentine's Day when I was asking him to come and see me and he was ignoring me he was there. I'm distraught, I did everything for him and his 3 children. I know his family and I'm close with his mum but none of them have mentioned him staying elsewhere. I've confronted him about this but he's just ignored me. I just need to vent. Not only that but I'm late on my period and I have a feeling I could be pregnant. What in the world do I do? I loved him with all that I am and this is how he repays me. I can't figure it out.Â