Address starting with 2, what mode I am in?
Both regtest and testnet use the same address prefixes for the legacy and p2sh-segwit address types. Addresses beginning with 2 are p2sh, and if retrieved via getnewaddress, are guaranteed to be p2sh-segwit.
For bech32 type addresses, the regtest prefix is bcrt and on testnet it is tb. You can try fetching a bech32 address to see what the prefix is and be more sure of which network you are using.

shouldn't the address start with 1 if its really regtest mode

No, and that would be dangerous.
Both regtest and testnet intentionally use different prefixes than mainnet. You will never see mainnet prefixes in those modes.